A couple of interesting and inexpensive i/v valve output stages

[ozcal]

What do you think guys?
Good base for upgrades?
http://cgi.ebay.com/DAC-I-V-conversion-module-SRPP-tube-module-/220825057033?pt=LH_DefaultDomain_0&hash=item336a32f709
http://cgi.ebay.com/SRPP-tube-output-module-coupling-transformer-/320738885804?pt=LH_DefaultDomain_0&hash=item4aad8700ac

[gthicm]

Not sure I would even bother with an SRPP output stage.  An anode follower would be more to my liking.  Have a look at the below.  Well made, extremely flexible and sounded great when I used one with a TDA1541A dac.  Not a bad price when you consider it is virtually plug and play, once configured, which is very simple with jumpers.  Tube not included.

http://www.diyhifisupply.com/node/399

[kajak12]

Not sure I would even bother with an SRPP output stage.  An anode follower would be more to my liking.  Have a look at the below.  Well made, extremely flexible and sounded great when I used one with a TDA1541A dac.  Not a bad price when you consider it is virtually plug and play, once configured, which is very simple with jumpers.  Tube not included.

http://www.diyhifisupply.com/node/399

Ozcal owns a satch dac and uses the circuit you recommended very average too much crap in it need some tlc,Its the last circuit i would use with a tda1541 dac

[gthicm]

Not sure I would even bother with an SRPP output stage.  An anode follower would be more to my liking.  Have a look at the below.  Well made, extremely flexible and sounded great when I used one with a TDA1541A dac.  Not a bad price when you consider it is virtually plug and play, once configured, which is very simple with jumpers.  Tube not included.

http://www.diyhifisupply.com/node/399

Ozcal owns a satch dac and uses the circuit you recommended very average too much crap in it need some tlc,Its the last circuit i would use with a tda1541 dac

Yes, I had a Satch dac too and was not impressed.  The issue is with the dac and not the output stage.  Also, the Satch may be configured in many ways and I found that I liked non oversampling and filterless.  I have no idea how your friend has set it up.  I sold the Satch long ago. 

There is a lot of discussion on the net concerning using SRPP as an output stage for a dac.  I have had a dac with it and was not impressed, so I tend to agree with the SRPP detractor camp.  Just my experience.

[kajak12]

Not sure I would even bother with an SRPP output stage.  An anode follower would be more to my liking.  Have a look at the below.  Well made, extremely flexible and sounded great when I used one with a TDA1541A dac.  Not a bad price when you consider it is virtually plug and play, once configured, which is very simple with jumpers.  Tube not included.

http://www.diyhifisupply.com/node/399

Ozcal owns a satch dac and uses the circuit you recommended very average too much crap in it need some tlc,Its the last circuit i would use with a tda1541 dac

Yes, I had a Satch dac too and was not impressed.  The issue is with the dac and not the output stage.  Also, the Satch may be configured in many ways and I found that I liked non oversampling and filterless.  I have no idea how your friend has set it up.  I sold the Satch long ago. 

There is a lot of discussion on the net concerning using SRPP as an output stage for a dac.  I have had a dac with it and was not impressed, so I tend to agree with the SRPP detractor camp.  Just my experience.

srpp circuit is very good if the correct tube and parts  are used  just my experience bb 1704 done correctly with srpp is a very good dac.

[gthicm]

Sure, an SRPP done right sounds fine.  As a matter of fact, I did play around with one on a Lite 60 with 1704 dacs.  There were a number of areas that could be improved.  One of them was the output stage.  I am familiar with some people who advocate SRRP, like Lampizator, but I think he is in the minority.  I have followed him for years and have made a donation to him, as his work is very interesting and informative.  I do not share his enthusiasm for SRPP.  As a matter of preference, I would not bother trying to rebuild the SRPP on Ebay for a dac, but that is just me.  I would rather start with a design I and many others prefer over the SRPP.

As to anode follower, the circuit is not inherently or as applied bad, but the implementation in some cases may be bad.  There are plenty of advocates of this topology, including but not limited to Audio Note.  Whatever issues you were hearing with your friend's dac were not attributable to the anode follower as a circuit design.  There had to be other problems there.

[ozcal]

Geez ,I can't catch a break these day's    ,first I get told my Transport is crap and now me dac is average  
Just as well I think it sounds OK
As for my Satch it has been heavily moddified : input stage removed and replaced by two 150ohm carbon composite resitors in parallel across input. All Nichicom Muse bp caps relaced by Nichicon FG ( what was in the spares bin). Sa7220  removed , reclocking clock removed , logic chIp removed. NOS , passive I/V. Obligato output caps in valve output replace with Ampohm Al foil in oil.
Next stage will be to add Choke to the CRCRC filter on the  valve stage  and replace the decoupling caps around the DAC chip with something better.Apparently the major issue with the Satch is noise levels in the power supply and to that end I am looking at replacing the diodes with Schottky type and upgrading the regulators.
I would love to hear a Killer dac in my system so I can hear how it differs in sound to the hot rodded Satch.
Mario if you want to give me some help improving the Satch I am always willing to learn and I am sure Murray would be interested too.

[zenelectro]

Not sure I would even bother with an SRPP output stage.  An anode follower would be more to my liking.  Have a look at the below.  Well made, extremely flexible and sounded great when I used one with a TDA1541A dac.  Not a bad price when you consider it is virtually plug and play, once configured, which is very simple with jumpers.  Tube not included.

http://www.diyhifisupply.com/node/399

Ozcal owns a satch dac and uses the circuit you recommended very average too much crap in it need some tlc,Its the last circuit i would use with a tda1541 dac

Yes, I had a Satch dac too and was not impressed.  The issue is with the dac and not the output stage.  Also, the Satch may be configured in many ways and I found that I liked non oversampling and filterless.  I have no idea how your friend has set it up.  I sold the Satch long ago. 

There is a lot of discussion on the net concerning using SRPP as an output stage for a dac.  I have had a dac with it and was not impressed, so I tend to agree with the SRPP detractor camp.  Just my experience.

SRPP is basically a common cathode with a cathode follower on top of it, so theoretically you get
to have your cake and eat it too

Common cathode stages are generally better sounding but have high(ish) OP impedance.

Cathode follower have low OP impedance but also a reputation for bad sound.

There are variations to SRPP that can get around this but they are more complex.

Choose your poison.

T

[ozcal]

G , thanks for taking the time to reply , interesting stuff.

[ozcal]

Not sure I would even bother with an SRPP output stage.  An anode follower would be more to my liking.  Have a look at the below.  Well made, extremely flexible and sounded great when I used one with a TDA1541A dac.  Not a bad price when you consider it is virtually plug and play, once configured, which is very simple with jumpers.  Tube not included.

http://www.diyhifisupply.com/node/399

Ozcal owns a satch dac and uses the circuit you recommended very average too much crap in it need some tlc,Its the last circuit i would use with a tda1541 dac

"Its the last circuit i would use with a tda1541 dac"
Why Mario?

[kajak12]

[/quote]
"Its the last circuit i would use with a tda1541 dac"
Why Mario?
[/quote]
Very simple reason i took a tda1543 dac to mcb's house and it better in every way to the satch.
ps:check your heater voltage ozcal on the e88cc see if its higher then 6.3 volts

[ozcal]

"Its the last circuit i would use with a tda1541 dac"
Why Mario?
[/quote]
Very simple reason i took a tda1543 dac to mcb's house and it better in every way to the satch.
ps:check your heater voltage ozcal on the e88cc see if its higher then 6.3 volts
[/quote]
That's kinda surprising , thought Thorsten was pretty good on the sub killer level TDA1541A DACS.
Do you have any idea why the Satch is underperforming?
Thanks for the tip on the heater voltage , will test it.
Want to bring the 1543 dac over for a comparo next time you are up?
Cheers,
G

[kajak12]

Sub killer level?
The satch would have a hard time coming on par with audio gd dac worth $500.00

[kajak12]

No matter what you do it will always be a average hifi dac unless you replace the valve output stage with a better one.
Ps:if you like it dont change it

[ozcal]

Mario , I think the Satch implementation that I have sounds pretty good in my system but as I have said before I haven't had a chance to compare it , in my system, to anything other than my old Dacmagic and the Gigawork big dac. So I am happy to entertain any suggestions as long as someone is willing to demonstrate what's better in my system and not get pissy if I don't agree. Food and drink will be provided  .

[vitavoxdude]

Mario , I think the Satch implementation that I have sounds pretty good in my system but as I have said before I haven't had a chance to compare it , in my system, to anything other than my old Dacmagic and the Gigawork big dac. So I am happy to entertain any suggestions as long as someone is willing to demonstrate what's better in my system and not get pissy if I don't agree. Food and drink will be provided  .

That sounds a generous offer Mr. G.  You'll have half the homeless down and outs round your place if this gets out! ;-)
It's always good to compare in your own home, system synergy is all important as I have found out on many occasions.  Different valve configurations will no doubt sound different but which one sounds better may end up being just down to personal preferences.  Have fun trying.
V

[kajak12]

Mario , I think the Satch implementation that I have sounds pretty good in my system but as I have said before I haven't had a chance to compare it , in my system, to anything other than my old Dacmagic and the Gigawork big dac. So I am happy to entertain any suggestions as long as someone is willing to demonstrate what's better in my system and not get pissy if I don't agree. Food and drink will be provided  .

One day gordon i will bring the tda1543 dac down to your house

[gthicm]

No matter what you do it will always be a average hifi dac unless you replace the valve output stage with a better one.
Ps:if you like it dont change it

A very bold statement. I could not agree less!  The Satch is a good dac for the money and the UTS is not a problem.  Again, the output stage from some Audio Note dacs use the same circuit.  Some lower priced AN offerings do use SRPP.  I guess that in your opinion Audio Note does not know what it is doing.  

The areas for improvement in the Satch dac are primarily in the power supplies and decoupling.  I had a very heavily modified AckDac that while very good, was not the last word in sound quality.  The Satch was in some ways better to me, I suspect mostly because of the different dac chips used.

[ozcal]

Thanks for the info on the Satch, G. I have corresponded with Thorsten regarding upgrading the Satch and his views re the psu are the same as yours.
With regard to decoupling improvements ,would you care to expand on this?
Thanks,
Gordon

[kajak12]

No matter what you do it will always be a average hifi dac unless you replace the valve output stage with a better one.
Ps:if you like it dont change it

 I guess that in your opinion Audio Note does not know what it is doing.  

Yes its a very bold statement i knew it would get some trousers flapping and hormones going!
regarding audio note i have only heard audio note dac 2.1
Audio note do know what they are doing they spend 2k to 3k on parts and sell a top of the line dac for 30k plus.They really do know how to make a good profit margin.