RH30: Does the "Boost" switch add another gain stage?

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Carl
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RH30: Does the "Boost" switch add another gain stage?

Post by Carl » Sun Sep 25, 2011 5:09 pm

I have been playing around with a new RH30 combo for a couple of days now and I'm having fun. :smile:

I have noticed that I can't get the same sound by raising the gain pot as I get when switching on the "Boost" switch, so my question is: Does the "Boost" switch add another gain stage?

I e Boost switch off = 3 gain stages like an old Plexi. Boost on = 4 gain stages like for example 2203/2204 (late 70's JMP with master volume) or does the Boost switch do something else?

/Carl

richard
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Re: RH30: Does the "Boost" switch add another gain stage?

Post by richard » Mon Sep 26, 2011 11:04 am

I've had my RH 30 combo for quite a while now and it sounds to me like another gain stage being introduced. I'm using more gain than I used to since I starting using Bare Knuckle pickups. They can take a lot more gain whilst still retaining clarity. The boost now adds a nice volume kick for solos which I didn't notice anywhere near as much when I was using a guitar with an SD JB.

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Re: RH30: Does the "Boost" switch add another gain stage?

Post by wallympls » Tue Sep 27, 2011 3:37 am

Yes its a Gain Boost mate
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Carl
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Re: RH30: Does the "Boost" switch add another gain stage?

Post by Carl » Tue Sep 27, 2011 7:20 pm

wallympls wrote:Yes its a Gain Boost mate
Thanks Wally, but we do understand that the "Boost" switch is a "gain boost". But the question was if the boost switch added another gain stage or not. (A gain stage in this case would technically be half an ECC83 and some resistors and caps).

The other alternative would be that it's the same number of gain stages, but that the gain was increased in one or two gain stages of the preamp.

It's no big deal, but I like to know what all my pots and switches are doing... :ugeek:

/Carl

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Re: RH30: Does the "Boost" switch add another gain stage?

Post by Giga » Wed Sep 28, 2011 3:55 pm

I've never seen an amp like yours up close but in my RK the boost is connected to an interstage attenuation tidbit. The "no-boost setting" bleeds more signal to ground between V1A and V1B than with the boost engaged.

Giga

kell

Re: RH30: Does the "Boost" switch add another gain stage?

Post by kell » Thu Sep 29, 2011 8:39 pm

Hi Carl,

no, the boost switch does not add another (tube driven) gain stage. It is done by a FET transistor. Saves money, space, assembly time and makes the amp cheaper.

Cheers,

Kell

richard
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Re: RH30: Does the "Boost" switch add another gain stage?

Post by richard » Sun Oct 02, 2011 1:07 pm

Kell, I'm pretty sure it's not a FET, sounds like another valve stage to me. Perhaps Wally can comment ?

kell

Re: RH30: Does the "Boost" switch add another gain stage?

Post by kell » Sun Oct 02, 2011 1:39 pm

Hi,

I had one half a year ago. I opened it and there is a FET – that's it. I know the difference between a tube and a FET-transistor.

Cheers, Kell

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Re: RH30: Does the "Boost" switch add another gain stage?

Post by Marc J » Sun Oct 02, 2011 7:46 pm

kell wrote:Hi,

I had one half a year ago. I opened it and there is a FET – that's it. I know the difference between a tube and a FET-transistor.

Cheers, Kell
But is the FET used for switching rather than gain?

kell

Re: RH30: Does the "Boost" switch add another gain stage?

Post by kell » Sun Oct 02, 2011 8:17 pm

Marc J wrote: But is the FET used for switching rather than gain?
No it isn't – sorry.

Cheers, Kell

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