Hello, Community. I've already successfully built my first tube amp (SE 6n2p (12AX7) + EL84) and transistor amp (Beta22). Now i'd like to advance myself in tube amplifier for speakers as Beta22 is more suitable for headphones. Now i'm looking for good schematic in order to build SE amp (hi-fi) with the following parameters: up to 6-10 Watts per channel, KT88 or EL34 tubes, ultralinear application.
Last edited:
I built the PA part of this and really like it. Very open. The PA part is the 6CG7 and KT88. Pretty low sensitivity so needs a preamp with decent gain or use higher mu input tube.
R18 was put in to raise Zout of the 6CG7. Removing would no doubt increase sensitivity.
mike
R18 was put in to raise Zout of the 6CG7. Removing would no doubt increase sensitivity.
mike
Attachments
Last edited by a moderator:
thank you for your comment but it looks like that 6CG7 is very hard to get in a brand-new condition. And i'd like to find a solid finished schematic without any need in redesigning
Last edited by a moderator:
The 6CG7/6FQ7 is in production. At a minimum, New Sensor offers the tube under the ElectroHarmonix (EH) brand and it's available with or without gold plated pins. 😉
Might want to consider the tubelab SE, more details here: Tubelab | Dedicated to advancing the state of the art in affordable high end audio.
and the tubelab forum here: Tubelab - diyAudio
You can build an ultra-linear version using the EL34 or KT88 (or KT120).
and the tubelab forum here: Tubelab - diyAudio
You can build an ultra-linear version using the EL34 or KT88 (or KT120).
Hello all. I'm sorry, it was my mistake that I didn't take into account music styles that I listen to. I prefer blues, rock, hard rock and country. For that case push-pull is what I need up to 12watts. After reading tons of articles I found out that tube really doesn't have primary influence on sound but output transformer does. Could you please recommend some "classic" circuits based on Hammond transformers (as I understand the ones are highly rated).
As far as i now the Williamson is a PP amp.
Here i found a nice little circuit,
THE FUTURE: UL KT88 9W SE Power Amplifier
And a modded version of myself (didn't build it) with Hammond transfos.
Mona
Attachments
Hi.
Do you have more information about the circuit?
Ok, I found it - AmpDesign.
Regards
Last edited:
From where do you take these projects? It would be interesting to read some reviews of this amplifiers
The Dynaco ST-35 is a well known and liked EL84/6BQ5 PP circuit and it is UL.
There is a another recent version of it on the diytube site that breaks up the 7247 into (which the 7247 is internally) 12AX7 & 12AU7 for more tube subbing as 12BH7 can replace the 12AU7.
Some have made P2P (point to point wiring) amps of either circuit. They can be seen on the diytube site.
The EFB (enhanced fixed bias) circuit by Dave Gillespie is recommended for output tube life and improved sonics. It doesn't need an extra PS. It can be found on the Tronola Electronics site. There are other schematics (modded for the EFB) for Fisher, Scott etc. amps on the Audiokarma site with many in the Fisher forum.
The Sherwood EL84/6BQ5 UL PP amp circuit is worth looking at as it is also well liked. The amps styling may have kept buyers away as it is not so common. They are said to to be well engineered though.
One could also drive the 7591/7868 tube with the same circuit used for EL/6BQ5 as it has the same drive requirements. Most of the amp makers back in the day did just that.
There is a another recent version of it on the diytube site that breaks up the 7247 into (which the 7247 is internally) 12AX7 & 12AU7 for more tube subbing as 12BH7 can replace the 12AU7.
Some have made P2P (point to point wiring) amps of either circuit. They can be seen on the diytube site.
The EFB (enhanced fixed bias) circuit by Dave Gillespie is recommended for output tube life and improved sonics. It doesn't need an extra PS. It can be found on the Tronola Electronics site. There are other schematics (modded for the EFB) for Fisher, Scott etc. amps on the Audiokarma site with many in the Fisher forum.
The Sherwood EL84/6BQ5 UL PP amp circuit is worth looking at as it is also well liked. The amps styling may have kept buyers away as it is not so common. They are said to to be well engineered though.
One could also drive the 7591/7868 tube with the same circuit used for EL/6BQ5 as it has the same drive requirements. Most of the amp makers back in the day did just that.
Last edited:
Great help, thank you very much! What is the influence of a global negative feedback to the sound? And what is the sound signature of pp tube amp compared to a transistor one? For example beta22 (I've recently built the one and I'm impressed by the sound)
Last edited:
What would you say about quad 2 amplifier? It is pp amp which I think I'm capable to build. But it's far more complicated than the amps specified above. But I have no idea about it's sound signature.
I forgot about the Tubelab SPP which is also well liked.
It's pretty hard to build a bad sounding circuit wize El84/6BQ5 PP amp so they say, and in my experiences the quality (re sonics) of the Output Transformers used are the biggest issue.
It's pretty hard to build a bad sounding circuit wize El84/6BQ5 PP amp so they say, and in my experiences the quality (re sonics) of the Output Transformers used are the biggest issue.
- Status
- Not open for further replies.