Anybody knows if there is a tube with single section, that is electrically equivalent to 6SL7? Also a single section equivalent
of 6BL7?
Alex Deveza
of 6BL7?
Alex Deveza
6AH4 is half of a 6BX7 (fairly similar to 6BL7), and I'm sure there must be a single triode that is half of a 6SL7, but I can't think of it. How equivalent do you need? Is it the mu, the maximum Va, or must it be truly and fully equivalent?
6SQ7 is pretty similar, but it has 2 diodes in it as well (you could always just ground them though)
Hi,
Yes, plus it contains a pair of diodes and requires a different socket (B7G), the 6AV6 I mean.
I remember looking for 1/2 6SL7 years ago and could find any, which doesn't mean there aren't any.
The SL7 has an Ra of 44K whereas the 12AX7 has 62K.
Cheers,😉
Yes, plus it contains a pair of diodes and requires a different socket (B7G), the 6AV6 I mean.
I remember looking for 1/2 6SL7 years ago and could find any, which doesn't mean there aren't any.
The SL7 has an Ra of 44K whereas the 12AX7 has 62K.
Cheers,😉
Maybe a 6K5? Most of them are old metal tubes, however.
Also a 6Q7 is like half a 6SL7 plus a couple of diodes.
These are old old old tubes 🙂
Also a 6Q7 is like half a 6SL7 plus a couple of diodes.
These are old old old tubes 🙂
...The loctal 7C5 is the equivalent of a 6Q7 and it would avoid the use of a top tap - the grid on the 6Q7 (and a potential hum source).
6SF5, 6SQ7 are octal hi mu triodes, 6F5, 6K5, 6Q7 with top cap. I think all have higher mu and higher Rp than 6SL7. 6SC7 is 6SL7 with common cathode - they're cheap enough to use as a single triode.
In miniature, 6AT6, 6AV6, 6AQ4, 6BK6, probably others.
In miniature, 6AT6, 6AV6, 6AQ4, 6BK6, probably others.
Cdeveza,
I don't think such a beast exists. However, I often use the 6SL7 - it's one of the best high mu tubes around, with a lovely sound and huge soundstage. I T-bar the two sections - with no loss of quality I can detect - that is, connect the two plates, the two cathodes, and connect two 1K grid stoppers, with each to a grid.
In this role the tube delivers an rp of 22K, mu of 70, and I use a 50K combined plate load. With 175V on the plate it runs 3.36mA, and has quite good drive. If your application can tolerate using the one tube for a single voltage amplifier amplification, this is the way I'd do it.
Cheers,
Hugh
I don't think such a beast exists. However, I often use the 6SL7 - it's one of the best high mu tubes around, with a lovely sound and huge soundstage. I T-bar the two sections - with no loss of quality I can detect - that is, connect the two plates, the two cathodes, and connect two 1K grid stoppers, with each to a grid.
In this role the tube delivers an rp of 22K, mu of 70, and I use a 50K combined plate load. With 175V on the plate it runs 3.36mA, and has quite good drive. If your application can tolerate using the one tube for a single voltage amplifier amplification, this is the way I'd do it.
Cheers,
Hugh
CAREFUL...
High Hugh,
For that to work without penalty both halves need to be perfectly matched...
I use that kind of configuration with a 6DJ8 type of headamp (MC Hammer) CCS loaded, and matching all section of two twin triodes per channel is a bit of a headache.
Pros are halve Ra, doubled Gm, halved req but...current hogging may occur...
It's a bit like putting caps in //, they're notoriously tough to perfectly share current creating a see saw effect on the whole circuit...
Well, not just caps...you know what I mean.
Cheers,😉
High Hugh,
For that to work without penalty both halves need to be perfectly matched...
I use that kind of configuration with a 6DJ8 type of headamp (MC Hammer) CCS loaded, and matching all section of two twin triodes per channel is a bit of a headache.
Pros are halve Ra, doubled Gm, halved req but...current hogging may occur...
It's a bit like putting caps in //, they're notoriously tough to perfectly share current creating a see saw effect on the whole circuit...
Well, not just caps...you know what I mean.
Cheers,😉
AKSA said:
Also worth noting, 6SU7 same as per 6SL7 but better
matched sections, works excellent for paralleling
sections.
Cheers,
Terry
DAMN....
Hi,
Sigh...I'm not alone anymore knowing this...🙄
Thanks for sharing, Terry...can I invoice you for my loss?
Cheers, 😉
Hi,
Sigh...I'm not alone anymore knowing this...🙄
Thanks for sharing, Terry...can I invoice you for my loss?
Cheers, 😉
Thanks guys
Thanks to all, I will check all recommendations out. I actually have a driver circuit for a 300B that is composed of 6SL7 and 6BL7 in a cascade configuration, with the 6BL7 as cathode follower that drives the 300B's. I happened to like this circuit very much, very musical. I use half of both tubes to serve each channel. I know a lot of people does not like this, but I never had any problem. Now, what I wanted to do is to build a mono-block amp using this circuit and I hate to just use one section of a tube.
Well, I guess I may have to use the closest tube and readjust the circuit for optimum performance.
Alex Deveza
Thanks to all, I will check all recommendations out. I actually have a driver circuit for a 300B that is composed of 6SL7 and 6BL7 in a cascade configuration, with the 6BL7 as cathode follower that drives the 300B's. I happened to like this circuit very much, very musical. I use half of both tubes to serve each channel. I know a lot of people does not like this, but I never had any problem. Now, what I wanted to do is to build a mono-block amp using this circuit and I hate to just use one section of a tube.
Well, I guess I may have to use the closest tube and readjust the circuit for optimum performance.
Alex Deveza
Re: Thanks guys
Why not use one envelope per side (for each of the SL7 and BL7), with only one triode actually wired into circuit. Use half A in the left, anf half B in the right, and swap the tubes between channels every so often.
cdeveza said:
Why not use one envelope per side (for each of the SL7 and BL7), with only one triode actually wired into circuit. Use half A in the left, anf half B in the right, and swap the tubes between channels every so often.
Brett,
Well, that is exactly what I meant on my last post that I would like to prevent.
Alex Deveza
Well, that is exactly what I meant on my last post that I would like to prevent.
Alex Deveza
cdeveza said:
Curious as to why. Same number of bottles, betcha the same or close to the same filament power required, probably easier to source and replace tubes etc.
Re: Thanks guys
Brett,
I thought that was the point - hard to split one between 2 monoblocks 🙄
Cheers,
Brett,
cdeveza said:
I thought that was the point - hard to split one between 2 monoblocks 🙄
Cheers,
Re: Re: Thanks guys
John,
You're not paying attention. In the left monoblock, use a 6BL7, of which you use triode section 1, with section 2 being unused. In the right monoblock, use <i>another</i> 6BL7 which is wired with triode section 2 used and section 1 not used. Periodically swap the different 6BL7 bottles between the different monoblocks to even up the hours of useage on each section. Ditto with the 6SL7's.
Make sense now?
dhaen said:
John,
You're not paying attention. In the left monoblock, use a 6BL7, of which you use triode section 1, with section 2 being unused. In the right monoblock, use <i>another</i> 6BL7 which is wired with triode section 2 used and section 1 not used. Periodically swap the different 6BL7 bottles between the different monoblocks to even up the hours of useage on each section. Ditto with the 6SL7's.
Make sense now?
Brett,
As to the reason why, I guess I am just not too comfortable to using a tube with one section not being used while the heater is running. What you suggest will definitely work, I just feel that it is a bit more elegant to use single triodes instead.
Alex Deveza
As to the reason why, I guess I am just not too comfortable to using a tube with one section not being used while the heater is running. What you suggest will definitely work, I just feel that it is a bit more elegant to use single triodes instead.
Alex Deveza