OPT performance - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs 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

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 8th March 2012, 12:44 AM   #1
diyAudio Member
Join Date: Jan 2005
Location: Denmark
Default OPT performance


I can buy some Fender guitar amplifier output transformers for little money.
I know these OPT can't normally be used for HiFi.
They are rated at 50W guitar sound.
Question: If I only load them with 20-25 W. Can they so be used for HiFi and have the whole frequency range?

Data from catalog:
Outputtransformer for 2x6L6GC/5881 4 + 8 Ohm / max. 50 Watt
Exact Transformer for Fender blackface and silverface models: Bandmaster, Bandmaster Reverb. Raa = 4k2


  Reply With Quote
Old 8th March 2012, 02:46 AM   #2
kevinkr is offline kevinkr  United States
diyAudio Moderator
kevinkr's Avatar
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
No idea, but guitar OPTs are generally deliberately designed to do things that hifi transformers are not, and generally use lower quality core materials and may be wound with little regard for things like leakage inductance. (Deliberately)

Edcor makes some pretty reasonably priced hifi opts that even with shipping should not be a deal breaker.

Hard to know any specifics about the transformer you are thinking of using since you did not provide a link.
"To argue with a person who has renounced the use of reason is like administering medicine to the dead." - Thomas Paine
  Reply With Quote
Old 9th March 2012, 06:55 AM   #3
diyAudio Member
Join Date: Jan 2005
Location: Denmark

I do not know the exact manufacturer, because there are many who make copies of these transformers.
I have found a copy on TubeAmpDoctor in Germany's website and also believe that Triode Electronics has a copy. Do not know if they are identical.

  Reply With Quote
Old 9th March 2012, 07:24 AM   #4
diyAudio Member
Join Date: Jan 2002
Location: nowhere
As Kevin said guitar opt are not wound for HiFi. Not to say they cannot be used. But they have very low inductance and if used down low you need to drive them with low rp tubes. So triodes are the only option, and the turns ratio you end up with, in addition to the power derating (b/c of the lower frequencies) will give you an amp <10-15watts. Unless they have a 2ohm output you can place an 8ohm speaker. Not optimum, but may work.
For a 'work-shop' amp they will probably do fine.
A better option may be to use them in a biamp setup and use them for the higher frequencies. But as Kevin also mentioned, the higher leakeage inductance and capacitance makes for potential poor HF response. Still likely they will perform decent enough.
  Reply With Quote
Old 9th March 2012, 08:24 AM   #5
diyAudio Member
Join Date: Jan 2005
Location: Denmark


  Reply With Quote


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 01:32 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2