Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Your opinion, please
Your opinion, please
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 14th September 2005, 08:45 AM   #1
croccodillo is offline croccodillo  Italy
diyAudio Member
croccodillo's Avatar
Join Date: Mar 2005
Location: Bergamo
Default YOur opinion, please

I found this schematic on the net, in an Italian site:


I'd like to know your opinion about it: is this a good schematic, how should it sound?
It s rated for 8W output.

  Reply With Quote
Old 14th September 2005, 03:10 PM   #2
plovati is offline plovati  Italy
diyAudio Member
Join Date: Mar 2005
Location: near Milan
This is an Nuova Elettronica project, originary designed for an EL34. There are several mistakes in the tube polarization. EL34 is overdisippating and ECC82 is working at too low voltage.

Power transormer runs very hot. Output transformers are of good quality but only for frequencies greater than 50-60Hz.
The OPT trnnies are good for a 6080 single ended, limited to 2,5W.

I tried a 6V6 pentode output with cathode feedback driven by a 6AU6, with the same trannies and the sound is pleasant, power output 4,5W, clean.

For a EL34 single ended, much better the Audiophile EL34 (serach in this forum) by jean Michel LeClerc (If I remember correct).
  Reply With Quote
Old 14th September 2005, 03:40 PM   #3
amperex is offline amperex  United States
diyAudio Member
Join Date: Feb 2005
Location: MI
Default Amp design is like a game of chess

Choosing a design for high performace is like a game of chess. You pick high performance parts and place them in the proper position & best operating parameters. Why spend money & time & end up with less than great performance.

If one knows better sounding tube families, do not use an inferior tube. Same with capacitors, power supply design, rectifier, etc.

I never had poor performance from a direct coupled preamp/driver design. I also like a 6P5GT to a 6SN7 or 6J5GT. I had best luck with Tung-Sol or Sylvania. I was also pleased with a RCA metal 6J5, but not other metal 6J5s- go figure. I also like 6V6GT triode connected when a true triode tube is not an option. I suspect without much experience a KT88 may sound good triode connected per what others have stated. I also believe the inexpensive Wing C 6550 with the rectangle hole (not all round holes) in the plate is a reasonable quality tube.

I prefer oil caps or polypropylene caps over any electrolytic cap. A minimal quality coupling cap is AuriCap unless one likes distortion from say a Sprague 715P orange drop or simular low quality capacitor. Best are reported to be the Russian teflon design.

If using a SS rectifier, use UF4007 for lower noise operation. I also prefer choke input filter in a LCLC configuration to the power tube(s) with an additional LC to the preamp tubes. If I have to use a capacitor input, use CLC to the power tube & another RC or LC to the preamp tubes.

Use a high quality audio transformer. I understand Hammond has improved some of their SE designs.

My 2 cents.
  Reply With Quote


Your opinion, pleaseHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
looking for opinion xxxwhezzy Car Audio 9 8th May 2008 03:53 PM
Opinion on a Mid Madmike2 Multi-Way 1 9th May 2005 03:24 AM
Your opinion on 813? Jax Tubes / Valves 5 16th January 2004 09:10 PM
Want your opinion! vdi_nenna Pass Labs 9 16th January 2004 03:27 PM
I need your opinion.. Richard Moon Everything Else 1 11th January 2004 06:14 AM

New To Site? Need Help?

All times are GMT. The time now is 06:34 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio