All octal Clubman build - questions

[bmccowan]

I just finished the chassis for a Clubman type 6V6 circuit. 6SL7>6SH7>6SL7>2x6V6. Sounds great after I fixed a couple of errors I had made converting from schematic to layout.
I have a couple of questions; Forum folks likely have some knowledge - and certainly some opinions.
1. The Clubman has a "brilliance" control. Like others have found, I find that control to be pretty useless; more like below average student than brilliant. Ideas on giving it some range, or should I just use that chassis hole for something else? I really like the Framus mid control - so maybe that?
2. It's borderline too bright - I'd rather not remove the bright cap - other options? very small cap?
3. I wired up the power rail just like the original Clubman - parallel dropping resisters. Other than the ability to make independent voltage changes is there an advantage over series?
4. Pin 1 on the 6SH7 is the shell - I have read both to ground it and to not ground it. I did not, but gator clipped it to test - no difference that I could hear. Any thoughts on this?
Schematic which I modified from one on this Forum is attached, as is a V chart and a couple of pics. Right now it has a 5Y3 - will experiment with higher voltage, but it does not need to be any louder or cleaner. This was a scavenger build, AO-43 PT and OT; Chassis from someone's abandoned project; modified turret board from an amp builder's closeout. 8H choke from a forgotten source.
 

[sluckey]

1... That pot is really a cut control. It cuts brilliance, not boost brilliance. Works well on my AC-15 amps.
2... Use the cut control to take the edge off the bright.
3... None that I see.
4... Put it on a switch. Label it "to shield, or not to shield.    I would just ground it.

[shooter]

 


was one of my best amps!  I left the brilliance in, but never used it, when it moved on, the new owner said the same, and he can play guitar   

[bmccowan]

Thanks. Cutting the brilliance all the way gets me to just the borderline. I like dark amps. I guess there is always the tone control on the guitar, eh?
Shooter

BitCoin, Broke Tooth

Love it. What I immediately noticed about this amp is the tight, very distinct bass notes. I do not know enough about electronics to know what the secret sauce is there, but its a very nice tone. I have wanted to try a pentode in V2 slot since reading about it in Merlin's book - glad I did.
I built a Z-28 type amp a few years ago using a 5879 instead of an EF86. I have an extra socket in that chassis, and this is making me think about putting a 12A_7 in front of that 5879.

[sluckey]

Put a .01 cap on the cut pot. Any better?

[shooter]

the tight, very distinct bass notes.

the musician that has my build said the same thing!
here's the oddity, mine is EL34 based with a tranny PI (ala Gibson :), PLUS I "plexi'd the pre!!


maybe you can find the "magic sauce" comparing the 2 

[bmccowan]

I'm having some magic sauce right now. Woodford's Reserve.
Thanks Shooter - that amp looks pretty interesting.

[bmccowan]

Shooter - that's an EF86 in V2? I have done much with EL34s, although I have a Fisher stereo power amp I fixed up
SA-300B with a quad of them - it's awesome!
Sluckey, I'll try the cap change after the Woodford's wears off.

[shooter]

 


I'm having some RedBud linage reserve 




never used pentodes in pre's

[bmccowan]

Hmm - some dry refreshment.

[HotBluePlates]

...2. It's borderline too bright - I'd rather not remove the bright cap - other options?  ...

Thanks. Cutting the brilliance all the way gets me to just the borderline. I like dark amps. I guess there is always the tone control on the guitar, eh? ...

Don't know if this was a mangled quote, or bmccowan is saying the amp is still brighter than desired.

If the latter, I'll make the dumb obvious statement and say, "Just remove the dang bright cap."

I don't recall if the Clubman 35 I once owned had a bright cap, but I never felt like it was too bright.  But it's been 20+ years since I owned it, and it was the version with an EF86 rather than a 6SH7.

[bmccowan]

Not a mangled quote. I just meant that it sounds best to me with the "brilliance" cut all the way. And I wanted to see if I could get it into a useful range without removing the bright cap. If I can't, I'll "remove the dang bright cap." I'm going to try Sluckey's suggestion first. Others would likely not find the amp too bright - I have some hearing issues. I built a Spitfire a few years ago and that amp was way too bright until I removed the bright cap. This amp is not that bright. It's also my inclination to tinker with my builds a bit once I have any bugs worked out; after all, there was never an all octal 6V6 Clubman so I anticipated tweaking some values.

[HotBluePlates]

Gotcha.  I play my AC30 Bass model with the Cut control full-up almost 100% of the time.  The old AC10 Twin stays in a similar spot.

[bmccowan]

OK - I changed the cut cap to .01 and so far like it better. I have some useful range on the cut control and it gives me more useful range on the treble control too - so thanks.
But (you sensed that was coming, eh?) I'm not very used to master volumes and I realized that the MV was having a large affect on the tone. The MV and cut are interactive in terms of tone. Turn down the MV too far and the tone gets brittle. So I went to school here and found some old threads about that. Including one that HBP and Sluckey kicked around 8 years ago. Now there are some settings that sound great, so maybe I just find the settings and play. But would this amp be a candidate for dual gang pot MV instead? I also have put a Hall VVR in some amps and liked it.

[shooter]

Turn down the MV too far and the tone gets brittle.

fwiw;
I've never liked MV post PI in a self biased amp, I move mine B4 the PI and call it PA drive 

[bmccowan]

Shooter - I think that might confuse me, or the amp, or both. The volume pot on this circuit is between V2 and V3 (PI). So if I got you right, that pot would become the MV and I would add a gain pot between V1 & V2? I'd be afraid of messing up the way V1 drives the 6SH7.

[shooter]

was more an observation, not a suggestion

[bmccowan]

I thought so. But I am interested in your suggestions too! I bought a few Hall VVR board a while back, and may try one in this amp. The tone is too nice to not play it, and it's LOUD! PP 6V6 amps are pretty darn loud when you are playing in the house.

[bmccowan]

I just went down the rabbit hole of MVs. Including extensive threads on this forum. Crossline, Lar-Mar, improved Lar-Mar, Ken Fisher, Mission, light bulb strings, padded rooms (I'll need one of those soon,) etc. etc. Let's see, where did I put those high priced sonic ear plugs I bought?