Hey all. Just wondering if anyone knew the effects (detrimental or else) of mismatching primaries on OT's.
Say a design called for 8k ohms, but I've got an OT that uses 6.6k ohms, or 16k ohms.
How would it hurt the amp/color the sound/change the feel?
Justin
Mismatching Primaries on OT
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jwpartain1
- Breadboard Brother
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phatt
- Transistor Tuner
You have picked a subject that is rather hairy.
I've never found much definitive comment on the subject but I did once use a very low pri on a bulid and it did have stunning results.
Not having all that much knowledge I asked King Tut if it was dangerous to use a 2k6 primary when the Valves where normally expecting 6k pri.
His answer was, Any OT can be used with any power tubes if you know what is going on. So go figure??
I think SE Amps are a little tricky but the average PP Amp running **SANE HT Voltage** then it certainly worked well for me.
My PP 6V6 build was way harsh with 6k6 and the much lower 2k6 OT was a massive improvement.![[smilie=a_partyguy.gif]](./images/smilies/a_partyguy.gif "a_partyguy")
From what I've read Some early Marshall's used 1700 Ohm pp Primary. (4xEL34)
Which might explain the very nasal sonic effect as you loose a lot of high freq by running lower primary than ideal. (which is what I figured would happen,, so it worked well for me)
Bear in mind most figures you read are referring to a flat hifi spec,,, not guitar Amps.
Obsolete Electronics had a bit of good info on the effects of different primaries but the site is now also Obsolete.
Phil.
I've never found much definitive comment on the subject but I did once use a very low pri on a bulid and it did have stunning results.
Not having all that much knowledge I asked King Tut if it was dangerous to use a 2k6 primary when the Valves where normally expecting 6k pri.
His answer was, Any OT can be used with any power tubes if you know what is going on. So go figure??
I think SE Amps are a little tricky but the average PP Amp running **SANE HT Voltage** then it certainly worked well for me.
My PP 6V6 build was way harsh with 6k6 and the much lower 2k6 OT was a massive improvement.
From what I've read Some early Marshall's used 1700 Ohm pp Primary. (4xEL34)
Which might explain the very nasal sonic effect as you loose a lot of high freq by running lower primary than ideal. (which is what I figured would happen,, so it worked well for me)
Bear in mind most figures you read are referring to a flat hifi spec,,, not guitar Amps.
Obsolete Electronics had a bit of good info on the effects of different primaries but the site is now also Obsolete.
Phil.
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jwpartain1
- Breadboard Brother
Thanks phatt! Problem is, I'm checking into a SE amp.
RG has a nice little Q&A on his site, but it doesn't answer this question for me.
I figured it would be safe, but just didn't know what the effects would be on sound.
Thanks again for the extra information!
RG has a nice little Q&A on his site, but it doesn't answer this question for me.
I figured it would be safe, but just didn't know what the effects would be on sound.
Thanks again for the extra information!