Dr.Mavashi
neonderthalotonalogist
A pain in the rectumdrier, huh? You really have to gut the power section for this one, right?
6550s into EL34 sockets
- Thread starter Dr.Mavashi
- Start date
Northwinds
New member
Re: 6550s into EL34 sockets
They sell socket adapters I believe???
They sell socket adapters I believe???
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Lake Placid Blues
New member
Re: 6550s into EL34 sockets
No 6550's use the same sockets as EL34's. All that must be done in most cases is change a few resistors in the bias circut, to change the adjustment range, so that the 6550's can be biased properly, Sometimes even that may not need to be done if there is already suffcient range in bias adjustment.
If your talking about an amp that doesn't have an adjustable bias pot, then this would present a good excuse to have one installed.
No 6550's use the same sockets as EL34's. All that must be done in most cases is change a few resistors in the bias circut, to change the adjustment range, so that the 6550's can be biased properly, Sometimes even that may not need to be done if there is already suffcient range in bias adjustment.
If your talking about an amp that doesn't have an adjustable bias pot, then this would present a good excuse to have one installed.
Northwinds
New member
Re: 6550s into EL34 sockets
I thought they fit personally but never have had an amp w/ 6550s in it. Good point, an adjustable bias is a good thing for any tube amp
I thought they fit personally but never have had an amp w/ 6550s in it. Good point, an adjustable bias is a good thing for any tube amp
Dr.Mavashi
neonderthalotonalogist
Re: 6550s into EL34 sockets
Please explain the unwashed what the adjustable bias pot does? does that mean that when I swap tubes with it I no longer have to take it to the tech for biasing?
Please explain the unwashed what the adjustable bias pot does? does that mean that when I swap tubes with it I no longer have to take it to the tech for biasing?
Sludgenutz
New member
Re: 6550s into EL34 sockets
A bias adjustment is like setting the the idle of an old carbed engine. Too slow an idle, the engine dies...too high, you are just wasting fuel.
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The whole point of 6550's is cleaner power, at higher volumes. Think cleaner bass instrument power! It is power that can painfully "pop" your eardrums, while still sounding clear.
Think John Entwistle of The Who! His tone was clear on bass, but huge!
It does no good to go through the trouble of modding/installing an amp for 6550's...just to wish you had more grit afterwards.
People tend to like 6550's with a set of transformers good enough/large enough to make use of the clean power, ala Sunn amps.
6L6/EL34 transformers are really no match to the "ear popping" thump available to the 6550 tube. If a person likes the dirt from 6L6 and El34's...just get more cabs.
A bias adjustment is like setting the the idle of an old carbed engine. Too slow an idle, the engine dies...too high, you are just wasting fuel.
-----------------------------------
The whole point of 6550's is cleaner power, at higher volumes. Think cleaner bass instrument power! It is power that can painfully "pop" your eardrums, while still sounding clear.
Think John Entwistle of The Who! His tone was clear on bass, but huge!
It does no good to go through the trouble of modding/installing an amp for 6550's...just to wish you had more grit afterwards.
People tend to like 6550's with a set of transformers good enough/large enough to make use of the clean power, ala Sunn amps.
6L6/EL34 transformers are really no match to the "ear popping" thump available to the 6550 tube. If a person likes the dirt from 6L6 and El34's...just get more cabs.
Lake Placid Blues
New member
Re: 6550s into EL34 sockets
To the Dr...You will need to have it biased with adjustable bias, but a pot, or variable resistor, allows whom ever is biasing it to adjust the bias more precisely to the exact set of tubes.
A lot of amps don't provide a variable resistor, but use a set resistor, so as long as you use tubes that are the same, or very close to the same, as the amp was designed for, the user doesn't need to worry about it. This is probably why Mesa usually doesn't have adjustable bias.
This is fine as long as you always use nearly identical tubes, but if you want to change tube types, or use tubes of the same type that bias up differently, or you want to try a different bias with your tubes, it's not so great.
Adjustable bias does however, make the user more dependant upon a tech, unless he/she learns how to do it themselves.
Keeping the bias unadjustable prevents the user that doesn't know how, from screwing up the amp, or melting down a set of tubes , and as long as the user can find the same tubes; he/she doesn't need to take it to a tech everytime.
To the Dr...You will need to have it biased with adjustable bias, but a pot, or variable resistor, allows whom ever is biasing it to adjust the bias more precisely to the exact set of tubes.
A lot of amps don't provide a variable resistor, but use a set resistor, so as long as you use tubes that are the same, or very close to the same, as the amp was designed for, the user doesn't need to worry about it. This is probably why Mesa usually doesn't have adjustable bias.
This is fine as long as you always use nearly identical tubes, but if you want to change tube types, or use tubes of the same type that bias up differently, or you want to try a different bias with your tubes, it's not so great.
Adjustable bias does however, make the user more dependant upon a tech, unless he/she learns how to do it themselves.
Keeping the bias unadjustable prevents the user that doesn't know how, from screwing up the amp, or melting down a set of tubes , and as long as the user can find the same tubes; he/she doesn't need to take it to a tech everytime.
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