Amplifier based on 2N3055 - Page 2 - 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 27th January 2003, 05:47 AM   #11
diyAudio Member
 
EchoWars's Avatar
 
Join Date: Dec 2002
Location: Left of the Dial
Here is the schematic for the ST-80. Nice little amp, and about as much power as you can get out of the 3055...

From here.
Attached Images
File Type: jpg st-80.jpg (95.1 KB, 3604 views)
  Reply With Quote
Old 27th January 2003, 02:02 PM   #12
diyAudio Member
 
Join Date: Sep 2002
Location: Raleigh NC
Send a message via AIM to Jared
www4.ncsu.edu/~jdchmiel/amp.zip

this is a zip of all the info that came with A Qkits amplifier kit I got once ampon a time that seems to be discontinued now. Anyways, it is rates 100x1@8ohm or 175x1@4ohm and i verified it at smoke X lots @ 2ohm. I am going to replce the fried 3055's with MJ15003's as it was reccomended to me on this board as being a better all around transistor. This schematic and parts list might help you get started tho..
  Reply With Quote
Old 28th January 2003, 01:58 AM   #13
ted is offline ted
diyAudio Member
 
Join Date: Dec 2002
Location: Chicago, Il
Default ST-120 has 2n3055 (Really)

On many versions of the ST-120 that were kit built, the output's were indeed 2n3055. Reviewing the parts list of my ST-120 Q5/Q6 were 2N3055 Dynaco Part # 571844. (Serial number 17828060).
Another test to see what version you have, look at Q3/Q4 (drivers). If they are 2n3053/2n4037 and NOT the TIP's, then you have a older kit version of the ST-120 that has not been modified.

On later models they did switch to a better output/drivers.

The reason a 2N3055 works is due to the regulated 72V power-supply. That's right the ST-120 actually had a regulated supply.
You may ask, but wait the 2N3055 has too low a Vceo. That is true but it does have a Vcer of 70 volts and a Vcb of 100V. Thus allowing a 2N3055 to just squeek in, assuming a little power supply droop.

The regulated supply is what I feel gives this amplifier it's unique sound even with slow outdated outputs such as 2N3055's.

  Reply With Quote
Old 28th January 2003, 02:07 AM   #14
halojoy is offline halojoy  Sweden
On Hiatus
 
Join Date: Nov 2002
Smile Elliots Project 12 - El Cheapo Improved Amp

Rod Elliots Project 12 - El Cheapo Improved Amp

This amplifier is with cheap and easy to find components
is an improved version of an old 2N3055 amp.

El-Cheapo - A Really Simple Power Amplifier
---------------------------------------------

Figure 3 - The "Even-Newer More-Improved" El-Cheapo

/halo
Attached Images
File Type: gif elcheapo_espp12.gif (10.0 KB, 3291 views)
  Reply With Quote
Old 28th January 2003, 02:17 AM   #15
ststone is offline ststone  United States
diyAudio Member
 
ststone's Avatar
 
Join Date: Jul 2002
Location: Marriott Assisted Living, Boca Raton, FL
At least this kinda crap has bypass c's
The 2N3055 has been around for over 30 years, do I hear innovation... come on.
crabby old guy building a tube pre amp
(its all a joke)
__________________
alleen vragen
  Reply With Quote
Old 28th January 2003, 02:33 AM   #16
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
Well, for what it's worth, I just switched an ESP3A amp from 2N3055/MJ2955 to the MJ15003/15004. There was a significant difference. It sounded pretty good before, but sounded far better afterwards.
I have some spare old 2N3055s if you wanna drop by to pick 'em up...
  Reply With Quote
Old 28th January 2003, 08:19 AM   #17
diyAudio Member
 
EchoWars's Avatar
 
Join Date: Dec 2002
Location: Left of the Dial
Default Re: ST-120 has 2n3055 (Really)

Quote:
Originally posted by ted
On many versions of the ST-120 that were kit built, the output's were indeed 2n3055. Reviewing the parts list of my ST-120 Q5/Q6 were 2N3055 Dynaco Part # 571844. (Serial number 17828060).
Another test to see what version you have, look at Q3/Q4 (drivers). If they are 2n3053/2n4037 and NOT the TIP's, then you have a older kit version of the ST-120 that has not been modified.

On later models they did switch to a better output/drivers.
Hmmm..I didn't know that. All the 120's I'd seen had the 3772's.

Live & learn.
  Reply With Quote
Old 28th January 2003, 08:53 AM   #18
diyAudio Member
 
Join Date: Sep 2002
Location: south yorkshire, UK
Phase Linear ( i.e. Bob Carver ) used a whole bunch of 2N3055's in the 400 series IIRC ( about 6 or 8 per channel ) to deliver 200 Watts....


Ray

nostalgia aint what it used to be....
  Reply With Quote
Old 28th January 2003, 09:25 AM   #19
UrSv is offline UrSv  Sweden
diyAudio Member
 
UrSv's Avatar
 
Join Date: Jan 2002
Location: Sweden
NAD 3020.

http://www.gmweb.btinternet.co.uk/nad3020pwrhr.htm
__________________
UrSv
Those who say it can't be done should not stop those who are doing it.
  Reply With Quote
Old 16th December 2003, 03:00 PM   #20
Zombie is offline Zombie  Sweden
diyAudio Member
 
Join Date: Feb 2003
Location: At home
Default MJ15003 in Quad 303?

Would it be any improvement in sound quality and do you have to re-adjust the bias?
Cheers,
Tom
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
the ultimate class A 2N3055 amplifier filippo22 Solid State 6 28th April 2014 11:02 AM
OP Amp based headphone amplifier. zebra100 Headphone Systems 32 1st October 2008 09:00 AM
LM3886 based amplifier russo Chip Amps 18 4th February 2008 11:27 AM
Dr. Amp Tripath based amplifier pepolman Class D 8 6th August 2005 06:28 AM
Op Amp Based Mosfet Power Amplifier Dusk Solid State 0 17th July 2005 06:13 PM


New To Site? Need Help?

All times are GMT. The time now is 12:01 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