A little while ago someone called Perugini advertised with the words
"super triode" in this NG. He put the linkhttp://digilander.iol.it/paeng/ in his post. There are other, quiteincredible things at this page. Take a look, for example, at "working
with the VT25920". It may be my Netscape messing up things here, but
sometimes I see some circuits with some quite astounding properties (for
tubes) and sometimes I see other things not related to tubes. See for
yourself if you see any anomalities. What is going on?Besides, if there really is such a thing as the "super triode" he's
on to something big, but the info tells very little. I also question the
authenticity of this "vtw" or "vt-omega" tube. But OTOH, he has the
native (very hard to find) data on the 6H30/6N30 on his site! And they
are accurate. Perhaps someone could give a little more info? Mr Perugini
himself? Just, as the heading says, what does this all mean? Just take a
I
love music., but i just dont have the money for it "high end" gear. I
am by far not an audiophile, and i do not aspire to be. How can i assemble a
system on DIY seperates, what references should i refer to for the plans of each
of these components and cables, and what would the total cost be. Tubes,
foreplay pre amp, full range drivers, tqwp & voigt pipes interests me.
Altough, i do not wnat to throw out the possiblities on solid state. I would
like to note that i do like bass and simplicity & purist designs. I am
looking for CHEAPEST solution to high end. Its a hobby for me to find these
hidden secrets. My gear now includes audiosource amp two, nht super two, an old
yamaha cd player.
Here
are some sub-$1000 ideas for a whole system, end to end.
1)
CD Transport: Philips CDM12, available at steinmusic.de
Cost: $200 or less.
2) Kusunoki/Convertus 4x TDA1543 DAC, wired directly to the I2S outputs of the
transport/CD player: $50.
3) Some amplifier ideas:
Bottlehead 2A3 monoblocks: $500 with tubes PAEng-Design
6c45 "spud" amp: $400-ish PAEng-Design6c45 push-pull: $600-ish
How cheap can you go? You can get SET output transformers for $30 or less (Hammond
makes one), maybe pair it with a 6EM8 tube. I bet you could do a stereo amp for
less than $200. Less bass with cheap OPTs, though.
LM1875
"gainclone" op-amp: $100. Good bass.
4)
Wire: pure silver with teflon tube as insulation, or make your own paper/cloth
insulation: $30
5)
Speakers: The very basic could be a simple TQWT design using Radio Shack or
Fostex drivers. Cost: less than $200.
Or: something based on the Eminence Beta12LTA. Good bass.
Or: Some Diatone P610s. ($300-ish)
6)
Go mono: I've been listening to mono. For a DIYer on a budget, it makes a lot of
sense. Your speaker and amp costs are cut nearly in half, and there's a lot less
building involved. Plus you can use ridiculously BIG speakers in mono, and it
doesn't take up too much room. How about an Altec 605? ($400-ish)
7)
It's easier if you have a small room and listen at relatively low levels. Less
speaker/amp demands.
It's
amazingly easy to build your own DAC. I did it. It was my first major
electronics project, and it worked on the first try (once I resoldered an
intermittent ground connection). You can go nuts on battery power because
everything runs on 5V supplies. The whole thing shouldn't cost you more than
$200--maybe less than $50 if you build it into your existing CD player (i.e. no
S/PDIF receiver), more if you go with transformer outputs. I point-to-point
soldered the whole thing, no circuit boards.
Right
now, lots of people seem to favor zero-feedback designs (see TNT-audio's
Convertus) and transformer outputs (see Andrea Ciuffoli's webpage, and PAEng
Design).
Posted by
Antonio Tucci on August 23, 2001 at 21:45:26
P.S.
For Dennis (ChimeraOne): in that site the author has reported interesting data
regarding the 6C45P tube ...!
Posted
by mqracing(M)
on August 24, 2001 at 08:39:09
In
Reply to: Super
Power Triode posted
by Antonio Tucci on August 23, 2001 at 21:45:26:
Hi
Antonio:
Thanks
for the leads to several interesting websites which also themselves linked to
several more interesting websites with some wonderful articles and schematics.
One
such addtional link I thought worth mentioning on it's own. It's at Jeff
Rowland's amplfier site. This article is a wonderful introduction to the theory
and operation of transformers. And it is written well enough for the less than
magnetics engineer to really get something out of it in terms of gaining an
appreciation of how these devices work.
About
a week ago Dave Slagle was asking about and wondering about "ideal"
models of trans and what these ideal models might look like or what features an
ideal trans would have... well... this article is at least one good shot at
providing an answer to this question as well.
here
is the link http://www.jeffrowland.com/tectalk2.htm
and,
Antonio, cool pages on all the
single tube amps and 6C45 circuit variations and implemenations.
The
6C45 is a rather revealing tube - anything poorly recorded can be very harsh and
annoying, while well recorded material has a wonderful clarity and detail. It
sounds like a large 417A in many ways.
There
was also a Prior
Discussion of this
amp a bit back in the archives. Doc B suggested a few changes to ease the
analytical sound - I've tried bypassing the filament, and already have grid
stoppers and ferrite's in place. I may try a few other changes including
changing the input 100K to 10K in the future. The latest valve issue also has
more info on the 6C45.
With
$2500 you'd be best off to buy a WHOLE NEW SYSTEM. Keep your CD player (for now),
and get all new amps and speakers.
The
simple and obvious thing to do would be to go to Bottlehead and get the straight
Bottlehead setup. Build a Foreplay first, to learn how to solder. Then their
Paramour 2A3. Then put together some Straight 8, Super 12 or similar speakers.
Aim for efficiency of over 95db. You could do all of that for about $1200, which
leaves you $1200 to build the tube amp of your dreams, now that you know what
you're doing.
If
you really want an off-the-shelf amp to plug into your system, and keep your
speakers, I'd recommend a Williamson-type pentode amp. Maybe a Jolida. But don't
expect triode glory.
If
you want something simpler/cheaper/cooler, try this:
6c45
amp from Stephan Perugini: about $500 Afterburner
speaker from Thorsten Loesch: about $350
$5000
might be TOO MUCH to begin with. It may be better to budget $3000 or so, or even
$1500...
There
are plenty of great kits out there. The diyhifisupply.com 300B kit has been
gettin grave reviews. Otherwise, consider the kits from Bottlehead and Welborne
Labs, both sponsors of this site. I owned the Welborne Moondog and have heard
the Bottlehead parafeed 2A3 amps. Great stuff....and around $1400.
For
speakers, I would consider the Oris 150 or 200 sets, or some homebrew stuff
using vintage gear. Altec stuff is relatively cheap and plentiful in the United
States. Go to eBay. An Altec compression driver+wood horn+15" woofer in
homemade bass reflex cabs is a classic setup. The Altec 604 is also a
super-classic. The Hammer Dynamics Super 12 and Bottlehead (I think they dropped
the Electronic Tonalities name??) Straight 8 are good designs.
After
looking into those closely, you will either find something to buy or be inspired
with some kooky ideas of your own.
If
you want to go even cheaper, consider a 6c45 amp from the schematics by
Stephan Perugini. $500 should do it for a stereo SET. He'll even sell you
the trannies, which are cheap because they don't have to deal with a lot of
current. That's about 1500 mW, so you will need very high ef speakers to pair
with it. (Or try his 2-tube one stage push pull, with 10 watts.) You could do a
pair of eminence Beta12LTs in an open baffle with a tweeter in between...or some
604s....total cost around $400-$500 and efficiency around 101db. That's a $1000
SET solution that could blow your mind. Buy music with the other $4000, or start
working on your DIY DAC. You can buy a transport from Steinmusic.de for $200 (including
shipping), add on a $50 zero-oversampling DAC stage, and have a source worthy of
your SET amps.
Posted
by Thorsten on
September 13, 1999 at 06:21:27:
Okay,
as no-one is really radical here, one or two from the fringe.
The
506.20 uses (if memeory serves) the CS4329 DAC Chip. The newer CS4390 sounds
somewhat better and is plug in compatible. So simply swap these chip's for
starters.
Another
interesting mod is to the Output Stage that reoplaces all the Op-Amp's and other
nasties by a simple Transformer SPECIFICALLY designed for that job.
All
of these should doable with a minimum of physical changes to the unit and are
reversable.
That
said, even under such conditions I still feel that the Crystal Chip's sound
rather dire, so best tweak is to buy a decent CD-Player.... Only they are really
thin on the ground....
I
have become convinced of the excellence of the 6C45PI
and would like to use it in this circuit, but im over my
head :) The 6C45 apparently runs happily at 220 Volts and
up to 250 max according to this http://digilander.iol.it/paeng/onetube_design_page.htm
so I believe that it can drive a steroid 300B, but I dont
know how to change it over. It would live with the
conditions in the amp but can it be substituted with
minimal changes and provide enough voltage swing and
drive for 10 to 12 watts ? Further can the 6C45Pi be used
with battery bias in this circuit ? If so does anyone know what
changes that would entail ?) Thanks for all the help
everyone , im slowly learning a little .
This has ben quite the expierience so far :)
I
am a DIY beginner, though I have an EE background. I have looked at a couple of
the battery powered Phono stages out there like Thorsten Loesch's Analog Addict
stage and Klaus Boening's Dr. Groove II stage. Both look like they can be done
by beginners and have good results. If anyone has built these, I would love to
correspond.
Anyway,
here are some questions:
1.
For the Analog Addict 'El Cheapo' phono stage, where does one find a 10H 30ohm
DCR inductor? If I could source this, I think I would start with this one first.
2.
Which battery chargers are people using - I found a source for Yuasa NP 2-12
batteries, but would like reqs on chargers for parallel charging.
3.
What's the difference between the OPA637AP and OPA637BP? I looked at the TI/BB
site and there is little mentioned. Are these different grades of the same chip?
4.
For the Dr. Groove, what 9V batteries/charger do people recommend?
5.
What are the maximum MM input voltages for clipping? My Goldring 1042 is rated
for a high 6.5mv. The El Cheapo was tested with this, but I am not sure about
the Dr. Groove (looks like I could always lower the gain to make it work).
Thanks
a ton. Reading the archives has made me eager to start a DIY project.
-MA
Posted
by MG16(A) on December 07, 2001 at 17:34:02
Hi,
I built a very nice tube phono preamp circuit that uses 2 sealed lead acid
batterys. http://digilander.iol.it/paeng/a_pspiced_low.htm
The project included a charger circuit based on the L200 integrated circuit. I
can find no parts suppliers on the web that carry the L200, in the USA.
I think it may be a European part. I currently use a Radio Shack charger that
takes 4-5 hours to charge each battery. It will only charge 1 battery at a time.
The filiments draw a constant 600 ma., and I am not getting enough listening
time between charges. I actually would like to go to double the batterys ,(parallel),
for the filiment supply,(It uses 2 for a 24 volt B+), which would be a total of
4 sla batteries.
I would like to buy 4 L200's, and build a charger that has 4 seperate L200
circuits, to charge all 4 batterys at the same time.
Does anyone have some they would sell me? Or know where I can buy them?
Thanks
mg16
Posted
by Thorsten(A) on February 04, 2002 at 10:45:18
Just
a hint. As explained in our private mails - the Adagio will remain a esotheric
animal. Before it got pushed into this direction I had for possible commercial
release made studies of a much simplified version that should however deliver
most of what the big brother does. This was discussed on an arcane HK based
Board, so I here repeate the entire conversion as Q&A....
Some
random conversations about the Adagio'lito
(little/lite Adagio) DAC
Q:
CS8414/PCM1716
DAC Kit, does anyone know who sells this DAC kit now? Anyone try? Any good?
A
(by T):
Try:
www.diyzone.net.
I
did try and I was not impressed by the sound. It is however still worth getting,
because you can cut the PCM1716 of and with a little skill fit a TDA1545 to the
PCB (Op-Amp Position) and re-use/rebuild the powersupplies to give you +5V for
the TDA1545.
Then
you have a simple, cheap but great 16-bit non oversampling DAC. I have designed
a tube output for the TDA1545 which with minor changes would work great with
such a non oversampling concept.
Q:
Is
your PCB for the DAC available for sale yet
A
(by T):
No
and it is unlikely to become available soon. most People want a full Kit and not
just a PCB and require more support than I can afford to give, so I suspect the
PCB's for DIY'ers are now permanantly shelved.
Q:
I
am really ignorant in digital audio. Can you show me how to change to the use of
TDA 1545. Was that a dropin replacement? Can I avoid the uses of IT/chokes as
described on your site that for TDA1541?
A
(by T):
It
is not a drop in replacement, in effect you cut away all the tracks around the
8-Pin Op-Amp and the original DAC Chip. Then you wire the whole thing up in the
classic "hard wired" fashion, it's only a few wires (3pcs for the Data
& Clock, one ground, one Powersupply) and a few resistors and capacitors.
But
basically you MUST be comfortable with DIY electronics, otherwise don't bother.
Yes,
for the 1545 I have a schematic on DJ's Cheap Tube Audio in the files section
which is meant for the cheap Marantz/Philips CD Players which also use the
TDA1545. However, it will require "re-tuning" of the Analogue Filter
to work well with non oversampling, at the moment the values shown are for the
oversampling filter used in the CD-Players....
I
checked the design through, here is what it should look like for Non
Oversampling (only changed values shown)....
The
load on the Output Should ideally be 100K or higher.
Also
note that the circuit discussed is suitable ONLY for the TDA1545, NOT for the
TDA1541 or ANY other Chip. The changed Values for the Filter noted above are
ONLY for non oversampling at 44.1KHz and are not valid at any other sample
frequency.
In
the same place (DJ CTA) there is also a Schematic for a "super regulator"
aimed at supplying the TDA1545.
The
whole resulting DAC (the Cheap DAC Kit, TDA1545 and above Valve Analogue stage
can probably deliver around 70 - 80% of the sound the Adagio offers.
Q:
I
will have to build the same from scratch - etching and drilling a pcb would not
be a problem. Do you think the schematics per following would be the same:
It
is exactly the Kit. All you need to do is to connect the TDA1545 Data Inputs to
the relevant outputs from the CS8414 and to add the two 11k Resistors and the
Decoupling Cap on the TDA1545 Reference pin (look at the Datasheet on the
Philips Web-Site).
Q:
hard
to believe by changing a few caps and resistors this would become a non-os.
truly amazing.
A
(by T):
NO,
NO, NO. The changes in
capacitors Values are to accomodate a DAC that operates without Oversampling,
they do not make (for example) a Philipc CD723 Player into a non-oversampling
one.
The
changes in capacitor values are needed as the Non Oversampling DAC has a
staircase type current output with the "steps" being spaced with a
44.1KHz Frequency. This leads realistically to several decibel HF rolloff.
By
making the a Lowpass Filter with a certain degree of "peaking" in the
response we can offset this rolloff. However this only required if the DAC
operates non oversampling. If the DAC is fed an oversampled signal, like in the
Philips CD-723 CD-Player this additional > 3db lift at 20KHz would be very
undesirable. So hence the change of values for this pecific application.
Q:
Do
you think it is beneficiary if I change the bridge rectifiers to tube? - I just
have a tungsol 5u4gb to spare. Whats the value of C6? Do I need to change the
caps and add a choke?
A
(by T):
Yes.
I would in fact recommend the full Supply from the design referneced below:
http://www.diyaudio.de/archive/dac2.pdf
Q:
Referring
to the schematics from the digilander.iol.it site, do I just "float"
Cc of the CS8414? Fsync connect to WS, Sck to BCK, Sdata to DATA? Mck will again
be "floated"?
A
(by T):
Yes,
this should work.
Q:
On
the TDA1545, I obtained the block diagram from the Philips website. There is a
Vref outlet from the Iref thro' a 33K resistor.
A (by T):
The
whole Vref shooting match is needed, also, make both resistors in the Vref
circuit 11k, this improved the dynamic range and is needed for my design. You
will also need the decoupling Cap, the better quality the better, Sanyo Os-Con
SH Series or Black Gate PK are minimum, Black Gate NX-HiQ are better.
Q:
Do
I need to connect this Vref somewhere? Also the Vref feeds a couple of Opamps.
Do I just ignore the Vref when I use tube analog stage?
A
(by T):
Other
than feeding it to the chip - yes. It has no further external application.
This
is the state of affairs so far, I doubt that there will be much more on
exchanges, as short of giving a full hands on tutorial this should cover it
anyway.
Other
items for reference in this context:
TNT-Audio
Convertus DAC design Documents (loads of background and so on, please read this
rather than bugging me):
The
Convertus uses 4 X TDA1543 instead of 1 X TDA1545, Input formats, most
connections etc are similar for both chips, main differences are the Reference
Pins.
The
TDA1545 suffers from variations in series production and AFAIK they are still
being "graded", it is worth getting the better grades.
Functionally
this chip mimics the Operation of the TDA1541, but it operates using CMOS (as
oppsoed to bipolar) circuitry and it has the dynamic matching reference
capacitors on board, plus it requires just one low current positive 5V supply.
Later
T
PS,
If there are specific questions the above references and converstions do NOT
cover, feel free to ask here, I'll endeavour to answer, but please note that
this whole thing is considered by me as "NOT SUPPORTED". So I'll
answer ONLY if I feel the question has general merit and if I have sufficient
time to answer.
Hi,
I don't claim to be an expert, but I am using a diy tube phono stage that runs
on (2) 12 volt, lead acid batterys published in Glass Audio a few years ago. It
uses 2 7308 tubes per channel, with riaa network between the stages. Was fairly
simple to build, and it sounds very good to me. Nice big airy soundstage, good
depth, plenty of detail, and quiet.
The article gives a schematic, and I designed a pcb board for it using Ron
Welbornes Assist program. If you want a copy, email me. I have no way of sending
it via computer, but could snail mail you a copy. Check it out here: http://digilander.iol.it/paeng/a_pspiced_low.htm
mg16
Hi,
I thought I'll share my Headphone Amp Building story with you. Actually,
J.Epstein suggested to me to do that.
Anyway,
I have been in the process of building a headphone amplifier for 8 months or so.
The very first version was a 6SN7 SRPP OTL as seen at http://headwize.com/projects/strain1_prj.htm
That
amplifier was probably the best version of all the ones that followed it until
my very last one. It sounded very bright, accurate, fast. Nice tight bass and
lots of treble. However, comparing to my 300B SE, it didn't have same feel of
depth, presence. Treble were quite harsh, which could be attributed for using
Solens. Sorry for using vague subjective terms.
I
decided to pursue SE transformer coupled design and put together an amp as seen
in the previous issue of Valve (I think it was #7). In that article author
described a very similar symptoms of his SRPP OTL experience and suggested a
6BX7 SE with Hammond 125A universal OPT as a solution. I found the sound of this
version to be a step in the right direction but inadequate for my listening
demand. In particular, I thought that 125A was incapable of producing the sound
that falls into hifi category. The bass was practically absent.
That
made me to look for better OPTs and I have had Jack Elliano(Electra-Print) to
wind a pair of OPTs with 5K primary, 32Ohm secondary (I have Grados), rated for
40mA of current. I also asked him to wind a set of plate load chokes just in
case if I decide to go with parafeed. Jack did a great job and his transformers
greatly greatly improved sound of that 6BX7 SE amp. I have tried parafeed ( I
hade to interleave OPT laminations for that) and didn't like it. If you do a
search on this site, you may be able to find a thread with my report on it.
Even
though 6BX7 SE sounded quite good, there was something lacking in it. It didn't
have good microdynamics. Sound was lacking in resolution. I tried to drive 6BX7
with 6SN7, later I replaced 6BX7 with 300B. Still no improvement in resolution.
I applied 11dB of Negative Feedback. It helped alot. However it took something
from the sound as well. As I understand it, negative feedback should not be a
measure to make a bad amp sound right. An amp should sound pretty much right
without NFB. So I wasn't satisfied with that version either.
Finally
(sorry for being too wordy), I followed Jack Elliano's suggestion to try a hi mu
triodes. In particular, he recommended 6C45Pi with its 50-60 mu and low Rp. I
have to say, that this is the best amp I have made so far. It sounds great.
Seems like everything finally fell into one piece: depth, presence, speed,
resolution, details.
I
don't claim that this my final version, but it seems to be a very good candidate
for becoming the one. I still will try to apply very little of NFB and do bunch
of measurements. The only problem with it is that I have way too much of
amplification for headphone listening level. Basically, I don't get to turn
volume pot past 3 o'clock.
You
can find few schematics of SE 6C45 amp on the web. Keep in mind that WE437 is a
very similar tube and you may use curcuites that use that tube as well. Here is
the one that I used: http://digilander.iol.it/paeng/high_sigma_vacuum_tubes_part3.htm
Please note, that that schematic uses 280-0-280 power transformer. using that
transformer will put the tube above max rated plate voltage. It may not be a
problem, as you may conclude from reading J.Epstein's reply to my post in Tube
forum: http://www.audioasylum.com/audio/tubes/messages/53952.html
I am using 190-0-190 transformer.
Project published in Glass Audio 2/98 by Stephano Perugini. It uses 2 7308
tubes per channel, and 2 12 volt lead acid batterys. Quite simple to build,
and sounds excellent. Detailed and transparent on top ,with good dynamics and
fairly good bass. Excellent soundstage.
I was getting maybe 6 hours of listening time between charges using 5 AH
batterys, and decided to build a regulated power supply to supply the 12 volt
filament and 24 volt plate voltages.
I used the schematic from Ron Welbornes website, (PS1 dual voltage, regulated
power supply using LT regulators), to build 2 positive sections of the supply.
I used an LT1085CT for the 24 volt plate supply regulator, and an LM317T
regulator for the 12 volt filiment supply section.
Large filter caps were Cornell Dublier, and film bypass caps were inexpensive
Xicon polypropylynes. Resistors were Vishay/Dale 1/2 watt metal films.
Rectifiers are Fast/soft Recovery types.
All parts were sourced from Mouser, except for the transformers, which are
mounted outside the main cabinet.
I bought a 12 volt / 2 amp and a 25.2 vct /450 ma. transformer from Rat Shack
for a few bucks each. I hand drew the pcb trace pattern on a RS blank copper
pcb board using automotive,( scratch touch up paint ),that comes with a fine
brush built into the cap.
I etched the board using RS Ferric Chloride. Took about 1/2 hour and then I
drilled the mounting pads with a 1/16 inch drill bit in a Dremil tool.
Power supply and signal wiring used was some left over Audioquest type 4 solid.
It sounds wonderfull and if its now noiseier than it was with batterys, I can't
tell. Its great not to have to recharge batterys though.
One thing about the circuit: It is a little low on the gain side. ,My Ortofon
X3-MC fed the phono stage, which fed a DIY Bride of Zen line preamp. The Boz
has a gain of only 15 db, and I couldn't get anything above easy listening
level.
I switched to the line stage of a Curcio Daniel, and it was much better, but
still wouldn't rock the house.
I bought a Grado red which has a 5-6 mv output, and now have all the volume I
need with the line amp gain controls at 3 o'clock. Haven't tried the higher
output cartridge with the BOZ yet. I am too busy enjoying the music.
Reccomended!
System:
Oracle Delphi MKII/OL modded RB250 arm/Grado red.
Stephano Perugini 7308 tube phono stage
Curcio Daniel tube 6dj8 linestage
DIY Single ended Glory 45 tube amp.
Modded Lascala loudspeakers.
Cardas quadlink biwire speaker cables and quadlink IC's.
MG16
7308 Battery powered tube phono project
is excellent.
Posted by mg16(A)
on December 16, 2001 at 16:37:52
If any one is looking for a great sounding tube phono preamp that you can
build yourself, try Stefano Perigini's "A Pspiced low voltage phono
preamplifier with harmonic distortion cancellation". It was originally
published in Glass Audio 2/98. The entire project is on the web here.
http://digilander.iol.it/paeng/a_pspiced_low.htm
I built it and am using it with an Oracle MKII/Rega O.L. RB250/Goldring
1022, and it sounds very sweet and musical.
It uses (2) 12 volt lead acid batterys wired in series for a 24 volt B+, and
12 volts tapped off to feed each pair of tube filaments per channel in
series.
I used Radio Shack 12 volt lead acid batteries with 5 AH capability. He
reccomends 7 AH available at Digikey. Total power supply cost was $50.00 for
the 2 batterys. (4) 7308'S on Ebay cost me $40.00.
There was only a schematic, and I did the pcb layout using ASSIST software.
Maybe $50.00 in passive components, and $41.00 for an 8" by 14"
deep sescom cabinet to house everything.
The soundstage is wide extending well beyond the speakers. Instruments can
be heard existing in space behind the speakers. Bass is full. Dynamics are
very good also. The top end is just slightly recessed, which is very
pleasing to listen to on most of my LP'S. On some records,(Frank Zappa;
Overnight Sensation), it is slightly too soft. I used Panasonic coupling
caps that I had on hand, where he reccomended Wimas. I think the Wimas may
liven the top a little, and plan on changing to them when I can get them.
All in all, it is worth far more than the $150.00 I spent to build it.
It was fairly easy to build, and worked great from turn-on.
There is a battery charger circuit schematic along with the preamp project,
but I use my 12volt car battery charger that I bought for auto use.
I used an 8 terminal screw type strip to connect the 2 batterys to the
circuit, This uses 3 of the screws. 3 other screws on the terminal strip are
connected to bannana jacks at the back of the cabinet to connect both
batteries in parrallel for charging. I need to remove the cover each time to
recharge, and switch the 3 wires from the circuit feed screws, to the
charger connected screws. Takes a few minutes, but some type of switching
arrangement would be more convienient.
I reccomend this to anyone desiring a really good sounding tube phono stage
on the cheap.
I have the pcb artwork stored, and if anyone is interested, send me a self
addressed stamped envelope, and I'll mail you a copy. Its not in the form
that I can email. Email me for my address.
MG16
Follow the link to "GA
Article" for the full description. I used Sovtek 6922's instead of
the more costly ECC188-SQ. They work fine. This was my first DIY project
and it went off without a hitch. I didn't even know how to solder when I
started out.
In Reply to: I
thought so posted by 2channelman on June 19, 2002 at 12:02:04:
If you're looking for an interesting phono stage DIY project check out
the battery-powered tube stage at this site:
http://digilander.iol.it/paeng/projects_frame.htm
Go to the link labeled
"GA article" for the full description.
I built this as my first
DIY project having pretty minimal knowledge of electronics and tubes.
Had to learn how to solder to do it. With the exception of the tubes and
sockets you can get all the parts from Digi-Key for well under $100.
Given the lower than usual voltages involved it seems a good project for
first-timers (safe). Mine runs on 6922's and sounds great!
Have fun,
Phil
P.S.
I don't mean to take anything away from Doc and the gang. This is just
an alternative for those that can't wait.
Posted by Sondek (
A ) on September 23, 2002 at 16:18:49
Has anyone done this pre amp before, I am new to this DIY thing, can anyone
tell me what actually are the value for the two capacitors shown on the
schematic, are they 0.47Uf & 0.1uf or 47u & 1u?
This is the link to the wed site and schematic.
I'm in the same boat that you are. I'm a newbie at this though, and I am
currently waiting for the stain to finish drying on oak base for my Battery
Powered Line Preamp
(http://digilander.libero.it/paeng/projects_frame.htm).
I was thinking of using this schematic and the power supply from the GA
Article Phono Preamp on the site, and expanding it to use 6 7308 tubes (5.1)
and a DACT 6 channel stepped attenuator.
I haven't done any power calculations or anything yet (gotta finish the first
project before moving the the next!)
It's a very simple circuit, and few inmates have built the Phono Preamp
with much success.
Hi,
Here is a great tube linestage that is not expensive, very simple to build,
and sounds excellent.
It uses a total of 2 7308 tubes, 4 capacitors, and 10 resistors, for a 2
channel line amp. It is designed to run off of a pair of 12volt/5amp/hr. lead
acid batterys, but I used a 6.3vac/2a and 25.6vac/.5a Radio Shack power
transformers that cost about $6-$8 bucks apiece. A pair of adjustable 3
terminal voltage regulators,($2.00 each, 1 set at 12.6 vdc for series filament
connection, the other set at 25.6 vdc for B+), 8 1n4002 rectifier diodes,($3),
a couple resistors, and
2 4700/35 volt electrolytic capacitors. The 7308 tubes were Sylvania green
lettering, bought on ebay for about $20.00 each. You can get phenolic or
plastic tubes sockets for $1.75 each. I did spend a little more on the
coupling capacitors,( I used Multicaps that ran about $20.00 for the four of
them, but Panasonic polypropylenes from Digikey are excellent sounding at
about 1/4 the cost.
Total cost with a little enclosure and line cord and switch is about:
$100.
The tubes are wired with one section of each tube being a constant current
source/plate load for the other section. Sometimes called SRPP.
The great thing about it is its sounds vert tube like with a nice wide
soundstage, 3d midrange, and slightly soft top end. Very fun to listen to.
Also, it is easy to upgrade later with better caps, tubes, volume pot,(I used
the Radio Shack 100k alps for $2.00), but upgraded later to a better one. It
sounds great even using the less than premium parts.
If you want to look into it go here:
http://digilander.libero.it/paeng/projects_frame.htm
good luck!
mg16
Follow the link to "GA Article" for the full description. I used
Sovtek 6922's instead of the more costly ECC188-SQ. They work fine. This was
my first DIY project and it went off without a hitch. I didn't even know how
to solder when I started out.
In Reply to: I
thought so posted by 2channelman on June 19, 2002 at 12:02:04:
If you're looking for an interesting phono stage DIY project check out the
battery-powered tube stage at this site:
http://digilander.iol.it/paeng/projects_frame.htm
Go to the link labeled "GA article" for the full description.
I built this as my first DIY project having pretty minimal knowledge of
electronics and tubes. Had to learn how to solder to do it. With the exception
of the tubes and sockets you can get all the parts from Digi-Key for well
under $100. Given the lower than usual voltages involved it seems a good
project for first-timers (safe). Mine runs on 6922's and sounds great!
Have fun,
Phil
P.S.
I don't mean to take anything away from Doc and the gang. This is just an
alternative for those that can't wait.
I'm modeling tube amps and just spent a half hour looking for some Spice
models I had for various tubes. I seem to have lost them somewhere, so
that's not happening again - Here's a link to Svetlana showing several Spice
models for tubes . A couple of other great sites are Duncan's
site (referenced by the Svetlana page) and the " PAEng
" site
.
'Spose I could have just copied the models to my local disk, but maybe some
of you will find them to be interesting. Besides, I probably would have just
lost them again.
Somebody ask...DAC's output into
Transformers.
The idea sounds good, but...
Many dac's happen to be of current mode output nature, and like to look into a
virtual ground. Audio nirvana is, I'm afraid, not that simple. Does it in
general work? Of course! I can live with reduced bass, if the rest is of
pristine musical quality. But that's my cup of tea.
there is a PSE design at
http://digilander.libero.it/paeng/pae.htm look very interesting, i am deciding
on a design to build, just got my 6c45 tubes. more suggestion are much
appreciated either on pre or amp
Now all you need to do is replace the
power supply diodes and caps with what reference audio mods uses (they have a
parts list), superclock it and then replace the entire analog output stage with
1:2 output transformers (I wonder if Magnequest makes any that are small enough)
and you'll really be cooking. For info on where to hook up 1:2 output
transformers I would contact K&K audio, or Andre Ciuoffoli or Stephan
Perugini (PAENG design - do a search) or anything the good ol doc can brew here
and tada.......you're in business. Let us know what you do with this.
I'm
modeling tube amps and just spent a half hour looking for some Spice
models I had for various tubes. I seem to have lost them somewhere, so
that's not happening again - Here's a link to Svetlana showing several Spice
models for tubes . A couple of other great sites are Duncan's
site (referenced by the Svetlana page) and the " PAEng
" site
.
'Spose
I could have just copied the models to my local disk, but maybe some of you will
find them to be interesting. Besides, I probably would have just lost them
again.
Hello Jose ,
go to devices , then to high u Tubes and then open part 1 on the paeng website .
There is a list of possible tubes for this amps like EC 8020 , 3A167M , WE 437
and E55L in pseudotriode mode . I have done this with 60 ohm cathode resistor
bypassed with 1000 uF and 140 volt plate voltage , then I have 55 mA current . I
made this with a regulated power supply and it sounds amazing . The most simple
"power" amp , I ´ve ever built . No hiss , no hum and no oszillation
, I have used grid stoppers , ferrite beads and very short wires .
Regards , AlexK.
Posted by AlexK
(
A ) on April 19, 2003 at 11:53:00
In
Reply to: Source
of 6C45s? posted by korneluk on April 19, 2003 at 06:31:56:
Hello Jose ,
I have built such an one stage amp with a E 55 L in triode mode , input with old
studio transformers 1:2 , gridstopper , the tube , cathode resistor and output
transformer , thats all . Look at the italian websites under www.paeng.it .
Regards , AlexK.
It's
a lovely-sounding amp. I would think that with a tube rectifier like a GZ37 or
5R4 a 600VCT/200mA tranny would get you there. With a lower-drop rectifier like
5AR4 you might need a 550VCT.
there is a PSE design at
http://digilander.libero.it/paeng/pae.htm look very interesting, i am deciding
on a design to build, just got my 6c45 tubes. more suggestion are much
appreciated either on pre or amp
thanks
Posted by Garland (
A ) on June 13, 2003 at 10:09:01
In
Reply to: I
still think so... posted by Charles Hansen on June 26, 2003 at 17:12:27:
I'm still in :)
Here
is a good link showing how closely related a follower is
to NFB.
http://digilander.libero.it/paeng/design_frame.htm
click on cathode follower
The
output signal in the follower case and the NFB case consists
of a power series, indicating harmonic multiplication.
What
I think you may be getting at is that if the follower device
itself is very linear, then the harmonic multiplication maybe
low in scale and thus hard to hear (although I don't like the way
they sound).
Don't believe everything you read about high B+ and transmitting triodes.
Many folks have been using 845's at low B+ with good results.
I
played around with 211's and finally settled on a B+ of 825v, 60ma as an
operating point. It gave me all of the power I needed and sounded wonderful. It
also allowed me to use some "reasonable sized" 15uf/1000v oil caps
instead of a few much larger parts I had.
I
was more impressed at the sonic differences made by altering the current than
the B+. Also the power supply made a substantial difference - liberal use of
swinging/smoothing chokes and smallish oil caps sounded way better than larger
banks of electrolytics. I'm not sure the 866jr's made any sonic difference, but
they sure looked better!
My
circuit is very similar to PAE's (see link below)
Hi,
Bottlehead Foreplay is very good for a couple hundred bucks.
Another hundred or so for the mods available, and it becomes a really great
sounding line12au7 line stage. IMO
Another great diy preamp I have tried is the Curcio mods for Dynaco Pas3's. $55
for line, phono, and regulator boards each. Stuff them yourself, and replace the
Pas's boards. Can get a nice Pas for under $200 to use as a base.
A strictly from scatch , battery powered , 7308 tube project is here. Click on
battery powered line and/or phono project. I built it last year, and it sounds
very nice.
Hello,
I am finding out for the good schematic of line preamplifier for tube 6H30Pi,
Could you please recommend some schematic for me? I found 1 shematic on the PAE
website as attached.
