6AS7 amp schematics

[edrel sison]

Hi to all,

New to this forum. I wonder if anyone could help to contribute some schematics of amps using 6AS7G as power tubes and 6BM8 or other tubes as drivers. Checked links from Svetlana Tech Bulletin (by Cyrus Brenneman) but links on circuit was dead. Will appreciate any design whether PP or SE. Cant afford OTL as I only have 4 of the 6AS7G tubes. Thank you very much.

regards,

edrel

 

[audiousername]

It's your first post, so welcome

Perhaps you were looking for something like the schematic attached?

 

[Stixx]

6AS7/6080

Hi edrel,

there have been a few threads on this forum about that subject. Just do a search using "6AS7G" or "lilliput".
One amp discussed was the Lilliput amp using E88CC/6922/6DJ8 as driver and the 6080 as output tube.
This one is still on my secret wishlist to build....!

And it involves way lower voltages than the svetlana/brenneman design...

rgds
Oliver

 

[planet10]

These guys seem to be using a cicuit very much like the Svetlana circuit in their little amp....

http://www.goldster-audio.com/

An externally hosted image should be here but it was not working when we last tested it.

dave

 

[audiousername]

Gee, that's a very nice looking amplifier... though I wonder how the while lilium improves the sound 😀

Even though it uses the same valve complement (6BM8/6AS7G), the vague description of "anode follower", "SRPP power triode" hints at a different design. Something perculiar is that the amplifier is sold with special speakers for it, which are specified with "600 ohm 45V connectors", so it may be some kind of OTL with a high impedance speaker - plus, there doesn't seem to be all that much room for output transformers... especially the rather large ones required by an SE design running at quite high currents as required by the 6AS7.

 

[rcavictim]

Dave,

What does the flower looking device do? Is it the antenna for the remote? 😀

 

[edrel sison]

Guys,

Thank you very much for wonderful replies and infos. I am certainly enjoying this forum. Yes I searched before posting this and I wanted to compare the liliput vs. the brenneman design. Thanks again.

Jason,

Thank you very much for the circuit. Yes I was asking for this. Would i am not be asking too much if i request posting here if you have a copy on your archive of the power supply circuit? There were two circuits on the svetlana site, the amp circuit and the power supply. Hope you have it. Thanks.

Good looking amp posted. Very nice. Hope my DIY project would come close at least on the way it sounds


regards,

edrel

 

[audiousername]

Your wish is granted 😎

 

[Yvesm]

These guys seem to be using a cicuit very much like the Svetlana circuit in their little amp....

http://www.goldster-audio.com/

dave

So cute !!

But I don't think so.
As audiousername pointed, the OPT's seem to be in the loudspeaker enclosure, and they say "3 wires special cable" 😕

And 600 Ohms looks good to load a 6AS7 SRPP 😉

Could be a really good idea !
Curious to learn. Yves

 

[planet10]

But I don't think so.
As audiousername pointed, the OPT's seem to be in the loudspeaker enclosure, and they say "3 wires special cable" 😕

And 600 Ohms looks good to load a 6AS7 SRPP 😉

A note i just got back from Goldster indicates that it is indeed not the same topology as the Svetlana -- just the same tube complement.

> 0/ is the amp PP or PSE?
It is SRPP (Shunt Regulated Push Pull).

> 1/ how are you using the pentode section of the ECL82? (i have put
> together similar, but much less elegant systems and used the ECL82 as
> the whole amplifier)
The pentode section is connected in triode mode class A.

So would it be possible for this to be an OTL. How high would speaker impedance need to be for it to work as OTL?

dave

 

[ErikdeBest]

This german 6AS7 reminds me of this amp...from a fellow member from Diyaudio. From this one we have a schematic 🙂

I think speakers must be about 600 ohm. Tomorrow I'm going to a small city here in the netherlands check some old stock of dutch speakers...a good pair of 9710 - 800 ohm would come in handy for this amp 🙂

 

[sanford1]

FWIW, I've found most of the Svetlana tech notes mirrored here:
http://216.87.144.102/svetlana/techbulletins.asp

They are not quite complete, but most of it is there.

 

[fdegrove]

Hi,

Since we're adding info:

This german 6AS7 reminds me of this amp...from a fellow member from Diyaudio.

The member you're refering to is Robert Morin IIRC.
It's been awhile so you may have to dig into the forum's archives to find more info but the amp is reported to sound fine and work reliably.

Cheers, 😉

They are not quite complete, but most of it is there.

Should anyone require more info, I have the entire ex-Svetlana USA site mirrored on one of the servers here...

Cheers, 😉

 

[edrel sison]

schematics

Thanks Jason for the power supply schematic.

I appreciate you guys also for helping out on my DIY project.

regards,

edrel