Stang Ray question

[chopstuck]

I got my Rocket-Ray sounding good with a couple of basic changes. The power supply works fine for both channels BUT The Stang channel likes the high voltage tap off the Heyboer Toneslut tranny and the rocket likes the low side. I put a big old switch in there to make it easy. The voltages on my pentode screen and plate only change by about 10v but the change in headroom and bass response is unbelievable. I also juggled the plate and screen resistor to get closer to the published voltages of about 106v on both. I got to 110v plate and 80v screen and left it. I may try to get them closer but right now they sound fine.

It's absolutely astonishing how a bit of power supply tweaking changes the frequency response of the pentode stage. Low V+ gets you less gain, more bass and a big hole in the mids and a bass hump. More voltage gets you more gain, pronounced mids and a cleaner tighter bass without a the big mid bass hump.

Makes my low E string sound like I'm playing a Twin ! It's got the percussion the Rocket lacks, the sweet midrange the Twin lacks. The Rocket has the grit the Stang and Twin lack. So best of both worlds....
Plus they both like that ol' Dynaclone OT so they make good neighbors

[Bear]

Chop, is the voltage difference for the whole amp or just the preamp?

[chopstuck]

The voltage is up for the whole amp.

That's what adds the tight and powerful bass.

Better for clean tones.

[telentubes]

The Stang Ray and my AC15 are very similar so I'll be converting the AC15 to a 2XEL84 Stang Ray while I wait for iron to arrive for other projects.

It was mentioned that the schematic and layout posted at the beginning of this thread are wrong. Are corrections available?

[M Fowler]

On page one of this thread I noted the schematic and layout are correct.

This one doesn't include the effects loop but otherwise good.

Mark

[telentubes]

The section I don't understand on the layout is where the wire from the Volume pot wiper leads down to the two jacks, back up on to the board, through R11, then C9 and on to pin 2 of V2.

There's no R11 on the schematic and the wiper goes directly to pin 2 of V2 after passing through C9 (.01uf).
I don't understand the loop through the jacks.

[M Fowler]

That is the effects loop send. I send you a PM.

[telentubes]

Thanks Mark,
I wish I could take back some of these embarrassing dumb questions some times. Effects loop duh

[M Fowler]

No problem I have asked worse than that.

[Drumslinger]

Hey Mark,

Was the effects loop on the standard SR?

[M Fowler]

I don't know I have the S series Stangray.

[daz]

I'm looking to building one shortly. My question is why is the first filter cap 50uf when 5u4GB are rated to accept up to only 40uf?

[Colossal]

My question is why is the first filter cap 50uf when 5u4GB are rated to accept up to only 40uf?

Daz,

The SR uses a GZ34/5AR4, not a 5U4GB. Some amps use reservoir cap values that exceed the published ratings. Usually for a GZ34, the accepted limit is about 40uF but electrolytics are not precision parts so some variance in their actual rating is expected. You can always modify the power supply to suit your needs.

[M Fowler]

That layout posted isn't that bad it does have two inputs when SR uses one, doesn't have an effects loop and it is lowering the voltage by using the 5U4 when the SR is using the 5AR4/GZ34.

Mark

[telentubes]

Here's a merge of an AC15 with the Stangray. So... 2XEL84 with an EF86 pre and an EZ81 rectifier. May need a little tone tweaking down the road but works well overall for now.