LSC preamp question

[Cheez]

As I (re)read the owner's manual for my LSC, it's not quite clear as to when V2 is in the signal. V1 is obvious - that's input and the "drive" portion of Channel 2.

For V2, it just labels one side as gain2 and the other as gain3, without mentioning when they are online. Is V2 used at all for Channel 1? Does Channel 2 use both sides of V2? Anyone know?

 

[strumminsix]

Here is what I thought:

V1 A = CH2 Drive Stage = Drive on 2
V1 B = Input Gain Stage = Input Gain on both
V2 A = 3rd Gain Stage = Output
V2 B = 2nd Gain Stage = Master on both

Maybe I'm wrong.

 

[Cheez]

Hmmm... then how would Channel 2 be "ganinier" (their word, not mine!)? I would think there's another gain stage there somewhere for Ch2...??? I suspect it's half (or all) of V2, but I'd like to know for sure.

Output should be the effects loop tube (V3).

 

[strumminsix]

Hmmm... then how would Channel 2 be "ganinier" (their word, not mine!)? I would think there's another gain stage there somewhere for Ch2...??? I suspect it's half (or all) of V2, but I'd like to know for sure.

Output should be the effects loop tube (V3).

Looking at the manual the LSC uses different pots for the Gain on the different channels, maybe that accounts for it?

I can totally see why you say the Output should be on V3.

Like I said above, I don't know for sure just making logical guesses.

 

[John G]

Hi,
On my LSC the second ch is 90% the same as a MK1 reissue, so the drive control switch is the same as plugging yer gat into the low then to the hi gain input. Ch 2 is gainer and but there is no additional tube involved, just extra gain/signal level hitting the tubes a little harder. In fact the whole amp is a two ch three sound version of the MK1 reissue with all the modern bells and whistles that the later Boogies have. These and other
small refinments plus attention to detail is what makes this amp sound so good. Having said that I will be changing the reverb cct and the effects cct in the future, as they don't seem to be tonally quite right to these ears.
John G

 

[Cheez]

Ch 2 is gainer and but there is no additional tube involved, just extra gain/signal level hitting the tubes a little harder.

You are correct, sir!

Called MB yesterday & talked to Mike Wolf. Five minutes later, there was a block diagram in my inbox. Regardless of channel, your signal goes through both sides of V2.

 

[strumminsix]

Would you please post that pic?

And thanks so much for the info!

 

[Cheez]

It's a .pdf... give me your email in a PM, and I'll send it to you.

 

[strumminsix]

PM in transit and thank you.

 

[strumminsix]

Thanks. BTW, ya notice anything odd???

The manual says:
NOTE: The Effects Loop RETURN jack can serve as a power amp input so that you may use the LONESTAR amplifier as a power
amp for either stereo reproduction or to incorporate additional pre-amps. Here are a few things to remember that will help you when
interfacing to the LONESTAR for use as a power amp only;
1.) Connect “Dummy” plug or loose cable to SEND jack. ( This prevents any possible loading that could result in diminished RETURN
sensitivity.)
2.) The OUTPUT Level will be the only active control on the Front Panel (the PRESENCE control of Channel 1 will be active only
when that channel is engaged - see #3 )
3.) The SOLO control may be used to footswitch to a pre-determined amount of boost when the footswitch is connected.
NOTE: Therefore, we recommend selecting Channel 1 when you wish to use the LONESTAR as a power amp.


But the diagram clearly shows the loop being after channel Masters and Presence.

I think the manual is wrong since I tried popping my POD into the return exactly as described below and the presence had no effect.

 

[Cheez]

I think the manual is wrong ...

I'd say you're right!