Thanks for the site Bob.........
Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Tubes4hifi VTA tube amp and preamp kits and all Dynakitparts.com products
I know Roger builds his amps a bit differently than everyone else. Here's a quote from the original RM-200 review:
"In describing his circuit to me, Modjeski advocated the use of low screen voltages and higher-than-usual plate voltages in the output stage. The RM-200 runs the screens and plates of its carefully matched set of four output tubes at 350V and 750V, respectively."
He is able to achieve somewhere around 10,000 hours of life from his tubes due to running them at half of max dissipation.
He gets similar results from his RM-10 which gets 35 watts from a pair of EL84s.
I swear I'm not trying to sound like an ad for his gear but I've done a lot of research on his amps and his tubes and I'm convinced the guy knows his stuff.
zx wrote:The 4 Counterpoint Amp i have owned...... most from the 80s-90.......
SA80,SA200,Both amps started blowing fuses.....never new why...the SA200 tuck out one of my B&W801 tweeter..........
Next was the SA220 this was to replace the SA200.....worket fine
Next the SA-4s....At the time my dream amps on paper ......Driveing a pr of Acoustat 2+2 ESL one amp Smoket , only one of the OTL amps flamed out......I did not mean to say all 4 amps smoket!
RM-200.......an i stan by what i have posted about the sound......an how it could not drive my Apogee Stages.......
That's an RM-200 Mk II by Music Reference. I WISH this was my amp!
As for what others say.....Just look up ARC amps an pramps you find raveing about the great sound!
But till you put these amps in your home.... you well never know if there for you.....
If you dont go you wont NO.......All this is just one mans O-pine
Thanks for the site Bob..............
tubes4hifi wrote:I've never heard an ARC that I like, they use so much SS in the power supplies that it kills all the tubes in the main signal path!
That's why I won't build any tube preamp without a tube rectifier. Now I do use an SS regulator in there, but it acts as a shunt on the voltage,
and it drops the noise level 60db, and sounds better than a huge bank of capacitors, and doesn't seem to change any sonic flavors like some other designs.
stewdan wrote:Deepee99 --
If you are talking 12X4 type tube rectifiers, as used in the PAS and Roy's SP series preamps and if they color the sound in any way.....
I have found that NOS Sylvania, TungSol, GE, RCA, Raytheon are all fairly consistent assuming that the test Good. When I looked thru my old PAS 2 and 3's I found that I used the Sylvania 12X4 rectifier. I don't think they colored the sound in any way.
If I remember correctly, the two prebuilt SP-type preamps that I bought from Roy both used the Raytheon 12X4.
Hope that helps,