Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: Dusk on July 19, 2009, 08:51:29 AM

Title: Tube Works Amplifiers
Post by: Dusk on July 19, 2009, 08:51:29 AM
Hi  JM Fahey
It has feedback but it's from the driver transistors, that drive the output mosfets, from the driver transistor the feedback goes back to a input IC chip(TLO 71...?)and not from the output side(mosfets).
Yes, i have a schematic for the Mosvalve 962,but not for the RT2100. The problem is ,my scanner is a Windows 98 type and my system is Windows Vista and the two cant' shake hands...i don't think(i will get a new scanner soon...money$$##).
My speaker iam using with these units, is a Peavey 112 Bandit Extension cabinet rated 75-80 watts,it is close-back.
The RT2100 has two 12ax7s in it's preamp sectionthere are no tubes in the Mosvalve962
Dusk
 ps i have a rack system that has Paia  stack in abox tube preamp that feeds a Hafler P-500 mosfet power amplifier
that driver a homemade 2x12 close-back cabinet 280watts or so rated modo bass there.....also sorry for the bad typing.
Title: Re: Tube Works Amplifiers
Post by: J M Fahey on July 19, 2009, 06:52:37 PM
Hi Dusk, thanks anyway.
Funny to see that one of them has no tubes at all.
Something I`ve made to solve the lack of a proper scanner is to take pictures of the schematic, maybe only one for a real small one, two for a letter sized one and splitting it in uo to four sections, for larger ones or real small lettered ones.
The trick is to take them in the sun, so the lens is sharper, the focus not as critical and the speed short.
Besides, I brace myself (or my arms) with something: books, a cardboard box, a stool, whatever, and try not to breath for a second. The results can be *very* good.
I guess the sound of your amp is good.
You can try mounting the speaker into a double-size box, or use two of them.
How does it sound with "the other" 212 box?
Good luck with your tests.
J M Fahey
Title: Re: Tube Works Amplifiers
Post by: Dusk on July 19, 2009, 09:17:31 PM
Hi JM Fahey

I have only played the Mosvalve 962 through the 2x12 cabinet,it still lacked bass,mind you i did't krank it.
I have a Fender all-tube bassman 100watt,i played with the Peavey 112 cabinet,plenty of bass.

Dusk