Top Hat Club -is it any more than a lightning with 6V6's ?

[Darkbluemurder]

Attached is the schematic of the homebrew EL34 Club Deluxe that I referred to above.

Cheers Stephan

Can I use this same schematic but just use 6v6's and 18 watt iron?

Yes, you can. Actually when I first built the amp I used 6V6s.

[jcat5503]

Can I use standard 18 watt iron?

What kind of headroom did it have with 6v6's?

What made you go to 34's?

[Darkbluemurder]

You can use a standard 18 watt iron if you want to use 6V6s. The standard 18 watt power tranny will not have enough heater current for EL34s but 6L6s may work. My build has a JTM-45 type power transformer.

Clean headroom is quite similar but the low end is tighter with the EL34s.

There was no particular reason to move to the EL34s. I changed just to see how it sounds and left it. I may try a pair of Winged C 6L6s though.

Cheers Stephan

[andrew]

Hello all, I heard a Tophat Super Fat Deluxe on Youtube. Could someone guess how it might differ from the Club Deluxe schematic floating around? Thanks.

[Gee]

I am in the process of rebuilding one of my favorite builds which is a Club Royale based on some of the schematics posted here. I added a VVR to regulate the PA & PI when I was doing a couple of other similar 18Watt amps. I can't remember what I did exactly so I have decided to document this particular build which is a keeper.

One of the issues of regulating the PA & Pi is that the pre-amp section remains at full voltage and needs attenuating before the PI. I originally put a 500k gain pot before the PI, but I would like to change it a bit to limit the maximum gain setting to mimic the Tophat's 220k/150k divider before the PI. (Matchless use 220k/100k here). What I think should work, is to have a variable resistor close to 150K that replaces the fixed 150k so that on max setting it would never exceed the 220/150 ration. The closest I could find in my parts bin was a 270k resistor, that if wired in parallel with a 250kB pot, with the center lug to one side lug, should create 130k variable resistor. I have never used this type of attenuation before the PI, so I was wondering if I am on the right track here? Can anyone confirm this?

I have attached a work in progress schematic that shows the gain pot before the PI.

[dass101]

Hi, I recently built a Lighnting clone with VVR, pretty close to what you did, and here are my findings:

Atenuation before PI doesn't work great, it changes the tone of the amp too much. Stick with the PPIMV, it's much better.
And, related to the above, you shouldn't scale the PI voltage, you should scale the screens and the plates (A, B in your schematic)

[Gee]

Atenuation before PI doesn't work great, it changes the tone of the amp too much. Stick with the PPIMV, it's much better.
And, related to the above, you shouldn't scale the PI voltage, you should scale the screens and the plates (A, B in your schematic)

Hi,
Having tried all 3 types of topology (in other amps) when using a VVR, i.e. PA only, PA&PI or whole amp, I vastly prefer scaling the PA&PI together. If you scale only the PA, then as you suggest you need a PPIMV to deal with the greater signal from the PI. If you scale the PA & PI, then you preserve the gain structure of the PA and the PI together and should just need to limit the signal into the PI. In some amps such as the Spitfire and LiteIIb, the Vol control does that nicely and you don't need an additional gain control before the PI.

[dass101]

I'll have to try the PI scaling in this case, but anyway shouldn't the plates in the PA be scaled also?

[Gee]

... but anyway shouldn't the plates in the PA be scaled also?

Yes of course. Sorry for not picking up on what you correctly said. The plates are indeed scaled and the scaling wouldn't work if they were not.

P.S. I have now corrected the schematic (above) to reflect the amp as it is built.

Thanks.

[Masco]

Hey Gee,
Have you tried the bootstrapped style MV at the PI? You basically replace the 1M R's with a dual 1MA pot. Feed the pots from the 10n caps, feed grids through 10k R's from the wipers, the cold side of the pots get connected to junction of Rk and tail R. You might like this style MV for some drive comp.

[Gee]

Hey Gee,
Have you tried the bootstrapped style MV at the PI? You basically replace the 1M R's with a dual 1MA pot. Feed the pots from the 10n caps, feed grids through 10k R's from the wipers, the cold side of the pots get connected to junction of Rk and tail R. You might like this style MV for some drive comp.

Hi,
No I haven't tried an MV in this amp. Part of the reason is that I think using the VVR to scale the PA&PI achieves the same overall thing but also in this particular amp, which is a re-build of a re-build..., I just don't have the space either.

[Masco]

Hey Gee,
Have you tried the bootstrapped style MV at the PI? You basically replace the 1M R's with a dual 1MA pot. Feed the pots from the 10n caps, feed grids through 10k R's from the wipers, the cold side of the pots get connected to junction of Rk and tail R. You might like this style MV for some drive comp.

Hi,
No I haven't tried an MV in this amp. Part of the reason is that I think using the VVR to scale the PA&PI achieves the same overall thing but also in this particular amp, which is a re-build of a re-build..., I just don't have the space either.

I just realized I misread your previous postings.
Maybe in a future build if you happen not to scale the PI...

[chopstuck]

OK I started this thread 2 years ago in December and I finally got around to building the Club Deluxe.
One of those rare instances where it powered up first try no smoke, burning hair or anything. I got just an hour to mess with it and put in some non-junk tubes and it's pretty interesting so far.
I built it with Hammond organ iron and a surplus Victoria Tweed Super chassis. My voltages are 30v higher across the board using a 5u4 recto but lower than Stephan's. My PT was 320-0-320. I don't think a 6V6 minds 373v on the plate anyway. The tone controls are really interactive, almost disturbingly so. I tried a bunch of different speakers and can say that boy, it really matters with this amp. A Signature alnico 12S hurts my ears and falls apart at mod volumes. Clubby likes JBLs though. Pics to follow.

Captain Chopstuck

[Gee]

I have been enjoying my Royale build but what I found was that the amp really only comes alive when the new gain control I tried was set on full.

With that in mind I rewired the divider before the PI to increase the minimum and maximum gain to approximate from the Matchless value to a bit more that the Vox setting. I also added the 220k resistor after the divider and before the PI mainly because Ken kept it in the Rocket.

I have updated the schematic below.

[chopstuck]

I put some good Rca 6V6's and the tone has improved but not the gain.
I will try the extra pot to the 150K to ground.

What is the purpose of the second 220k resistor in the divider ?