|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: Holy Grails? posted by Allen Wright on April 9, 2004 at 23:59:25:
Having the pleasure of Allen Wright as a guest last fall, I got to see the schematic of his new DPA-300B, and hear it compared to the Aurora and Gary Pimm's PP47 amplifier - a trio of interesting PP amplifiers.
The biggest difference between what Allen is doing and my work is a matter of personal style - Allen likes balanced cascode front end/driver circuits and RC-coupling, while I avoid cascodes and use only (wide-bandwidth) transformer coupling. This gives a different presentation to the sound, hard to describe in the usual hifi terms, but evident on direct comparison.Probably the biggest difference (and some Asylum members may disagree with me here) isn't the circuit per se, but the sonic character of RC-coupling vs interstage-transformer coupling. To my ears, these sound quite different.
When I started the Amity project in 1995, I had never heard an interstage-coupled amplifier before - hearing the Sakuma amps was still two years in the future. (I was quite surprised to discover the Sakuma amps actually sounded totally different than the Amity - something I would not have expected.)
The Amity was unusual because it was both my first vacuum-tube design project and also because I wanted to create an amplifier with the lowest possible midband distortion in each stage of amplification. DC coupling with active loads could also do that, but my previous experience at Audionics with direct-coupled transistor amps had made me wary of cascading failure modes which can be dangerous with DC-coupled designs. So the Amity was very much a "thought experiment" - the math said it would work, but I had no idea how it would sound. The Ariel was a thought experiment as well, but combining an MTM with a transmission-line was less radical than reviving a mid-Thirties WE design with modern parts.
Listening to the Aurora has been educational - I can now easily hear the character of the SE stage compared to a balanced circuit, which is why I'm going forward with a new amplifier.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Quick Comments - Lynn Olson 19:20:38 04/10/04 (19)
- What is Your New Amplifier? - TonyB 07:48:04 04/13/04 (18)
- Here - Lynn Olson 14:30:43 04/13/04 (15)
- Thanks, Lynn. nt - TonyB 06:08:19 04/14/04 (0)
- Value of bypass capacitor on output. - Mark Kelly 22:24:53 04/13/04 (13)
- None of the above - Lynn Olson 00:38:34 04/14/04 (12)
- Re: None of the above - Henry Pasternack 14:23:09 04/14/04 (3)
- Various Bypass Stuff - Lynn Olson 02:17:54 04/15/04 (2)
- Re: Various Bypass Stuff - Henry Pasternack 14:55:58 04/15/04 (1)
- Good Question - Lynn Olson 15:31:32 04/15/04 (0)
- the style difference between me and Allen... - Allen Wright 09:04:05 04/14/04 (0)
- OK I'm just interested in intermodulation cancellation of odd harmonics. - Mark Kelly 01:27:38 04/14/04 (6)
- Deep waters there, good luck - Lynn Olson 01:50:27 04/14/04 (5)
- Yes - Mark Kelly 02:55:09 04/14/04 (4)
- Variables to play with ... - Lynn Olson 04:31:24 04/14/04 (3)
- I want to be shipwrecked and comatose... - Mark Kelly 05:32:39 04/14/04 (2)
- I hope you (and all the rest of us) succeed - Lynn Olson 01:56:55 04/15/04 (1)
- Your loop discussion was what rekindled my interest. - Mark Kelly 04:02:42 04/15/04 (0)
- The new amplifier... - gdahl 08:18:02 04/13/04 (1)
- Thanks, Gary - TonyB 08:25:49 04/13/04 (1)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
