Post your Solid State pics here. - Page 230 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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
Reply
 
Thread Tools Search this Thread
Old 14th March 2012, 12:45 PM   #2291
diyAudio Member
 
Join Date: Jan 2012
Location: Huddersfield
Wengtech

Your amp looks to be slightly older revision of mine, i cant see any delay on relays or dc protection circuits.

I goy lucky with mine and it fired up first time and has been running great for a month or so, i have some scans of the latest manuals and component additions if they are any use to you.

best regards james
  Reply With Quote
Old 14th March 2012, 03:19 PM   #2292
masood is offline masood  India
diyAudio Member
 
Join Date: Dec 2010
Location: fatehpur
Quote:
Originally Posted by hpasternack View Post
I had an extra set of SymAsym boards and I decided to use them to rebuild an old amplifier. The layout is a bit unfortunate, but workable. Since the heatsink assembly was made for TO-3 transistors, I chose to use a set of 2ST2121/5949 outputs. The amplifier is unconditionally stable and has a 450kHz bandwidth.

Here we are, work in progress.

-Henry
can you show me pcb.
thanking you
  Reply With Quote
Old 14th March 2012, 04:23 PM   #2293
diyAudio Member
 
Join Date: Sep 2002
Location: New England
Quote:
Originally Posted by masood View Post
can you show me pcb.
thanking you
The boards are the original SymAsym 5.3 design, as described here:

http://www.lf-pro.net/mbittner/Sym5_Webpage/symasym5_3.html

I kept the board as is, but used the TO-3 outputs on sockets with short wires connecting them to the board.

Here is another diyAudio thread about a redesign of this PCB specifically to use TO-3 outputs:

http://www.diyaudio.com/forums/group-buys/187592-3-symasym.html

With no offense intended to Mr. Bittner, who has designed by all accounts a very fine circuit, his original PCB design had some shortcomings and a number of improved layouts have been published. For instance, I have built AAK's dual output transistor version of the SymAsym with good results. If you search the forum you can easily find these discussions.

-Henry
  Reply With Quote
Old 14th March 2012, 04:34 PM   #2294
diyAudio Member
 
Join Date: Sep 2002
Location: New England
Quote:
Originally Posted by AndrewT View Post
HP,
the test assembly shows your PSU connections.

You have at least two tappings from the PSU Zero Volts.
One on the left cap to the left channel and one on the right cap to the right channel. This is wrong.

The three wires from the PSU to each amplifier, zero volts +ve -ve, should be twisted as a triplet and taken to the amplifier as that triplet. At the amplifiers (since it's two channel) the triplet is Y split to form two sets of triplets. One set to each amplifier. Keep these final triplets as short as possible and use low resistance wire in the Zero volts between the two amp boards.
Thank you for your very correct observation. If you were to zoom in on a high-resolution version of the photo, you would see the stubs of black wires adjacent to the transformer center tap connection on the bus wire between the capacitors. This is where the circuit board power grounds were originally connected. For a test lash-up, I was not concerned about punctillious grounding.

FWIW, the chassis with the power supply was a breadboard that I used for testing the complete amplifier before I eventually built this:

http://www.diyaudio.com/forums/solid-state/96192-post-your-solid-state-pics-here-226.html#post2907972

The final version of my latest amplifier will have a dual-mono power supply with correct grounding and modern filter capacitors. (Those Sprague blue cans are 30 years old!)

-Henry
  Reply With Quote
Old 14th March 2012, 04:51 PM   #2295
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
Quote:
Originally Posted by AndrewT View Post
HP,

The three wires from the PSU to each amplifier, zero volts +ve -ve, should be twisted as a triplet and taken to the amplifier as that triplet. At the amplifiers (since it's two channel) the triplet is Y split to form two sets of triplets. One set to each amplifier. Keep these final triplets as short as possible and use low resistance wire in the Zero volts between the two amp boards.
triplets ? i don't think so Andrew always ground is supposed to be out of the "twisting" twist rails together yes but ground never with them .
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  Reply With Quote
Old 15th March 2012, 09:24 AM   #2296
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Sakis,
think about it a bit more.
__________________
regards Andrew T.
  Reply With Quote
Old 23rd March 2012, 11:26 AM   #2297
kees52 is offline kees52  Netherlands
diyAudio Member
 
Join Date: May 2009
Location: Sprang-capelle Holland.
some little test with a hybride, mosfet dc driven by a 6C19 and a srpp 6N8, the 6C19 is not a cathodefollower but a plate follower driving the mosfets, I did need a high current low mu tube because of the mosfet capacity and to not to use feedback.

The printed circuit is made with a dremel, because it is just a tryout how a hybride without a cathodefollower sounds, this one has none, the 6n8 is not yet soldered that happens today.
Attached Images
File Type: jpg 01032007132.jpg (526.3 KB, 926 views)
  Reply With Quote
Old 23rd March 2012, 02:47 PM   #2298
diyAudio Member
 
Join Date: Mar 2012
Quote:
Originally Posted by kees52 View Post
some little test with a hybride, mosfet dc driven by a 6C19 and a srpp 6N8, the 6C19 is not a cathodefollower but a plate follower driving the mosfets, I did need a high current low mu tube because of the mosfet capacity and to not to use feedback.

The printed circuit is made with a dremel, because it is just a tryout how a hybride without a cathodefollower sounds, this one has none, the 6n8 is not yet soldered that happens today.
Wow, far out. I'm a great believer in hybrid amps. I'm guessing it should sound smooth.
  Reply With Quote
Old 23rd March 2012, 02:57 PM   #2299
diyAudio Member
 
Join Date: Mar 2012
There are some pics of mine on another thread.

Hybrid DIY cct of LM3886+6N11

It's as ugly as a Borg mothercube (I build speakers really...
http://alacrityaudio.files.wordpress...g?w=640&h=1031
) but it scares me to death. It'll creep up on you from nowhere and leave you shell-shocked, wondering just how did it do that...
  Reply With Quote
Old 23rd March 2012, 03:32 PM   #2300
kees52 is offline kees52  Netherlands
diyAudio Member
 
Join Date: May 2009
Location: Sprang-capelle Holland.
I have now everything soldered, how it sound I do not now yet, a version of it with cathode follower works here for already 4 years, still with wires and no pcb.

this has a p follower to test, it is a pcb made with dremel, and some old parts for testing it, It is ready for the big test after cooling is ready, LM350 is also on board now with supply.

Do it work nicely I make a board for it.
Attached Images
File Type: jpg 01012008039.jpg (785.9 KB, 819 views)
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 03:49 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2