New RAM tubes = Wow!

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corndog71

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New RAM tubes = Wow!
« on: 27 Aug 2013, 04:25 pm »
I recently ordered a quad of RAM matched Russian EL84 tubes and had to report on what I heard last night. 

To back up just a minute I recently rebuilt my already modified version of the Dynaco ST35 amp.  Rather than the traditional 12DW7 driver tube I'm using a RAM tested 5751 for voltage gain of both channels followed by a 12AX7 or 12AU7 phase splitter for both channels.  Eventually I want to rewire the latter for a 6CG7.  You know... for fun. 

I modeled my rebuild as a cross between Roger's amps and the classic Dynaco ST70.  I think it turned out pretty good-looking. 



Anyway, after living with a set of "matched" tubes from another vendor and having at least 2 of them start squealing on me at warm up I was ready to see if Roger's tubes would work better.

And holy crap do they!  The first thing I noticed thankfully was that everything was dead quiet on start up.  I set the bias and played some music at low volume for a couple of hours to let them warm up for a while.  Eventually I was able to sit down and listen and I noticed something was wrong right off the bat.  I had a feeling one of my speakers was out of phase and sure enough I found that was the case.  After fixing the speaker connection I sat down again and was impressed by the clarity I was hearing but now felt the need to adjust my speakers a bit.  Once I got them into a better position I sat down again and listened. 

The most obvious difference was depth.  Some recordings shifted back a good 5-6 feet behind the speakers!  Detail was excellent and the dynamic range seemed better than ever.  I'm amazed at the difference a properly matched set of tubes can make in this little amp!  I was enjoying it so much I passed out in my seat!  I have a pair of modified Dynaco Mark IV's I've been trying to sell but now I think I may retube them first and see if they may be worth hanging on to.

Highly recommended!

rbwalt

Re: New RAM tubes = Wow!
« Reply #1 on: 27 Aug 2013, 08:11 pm »
i only get my tubes from roger. i think his tubes are the best. no one tests or grades tubes as well as roger. i have some JJ E34L's coming this week to put in my RM9SE. they will replace the NOS Siemens EL34's that the amp came with from roger. so i will posting after they get some time on them. i keep saying that people should get their tubes from roger exactly because of what you are experiencing. i am sure they will only get better with time.

corndog71

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Re: New RAM tubes = Wow!
« Reply #2 on: 31 Aug 2013, 09:27 pm »


All RAM tubes now!  5751 for voltage gain, 6CG7 for phase splitter.  It sounds sublime.  :notworthy:

rbwalt

Re: New RAM tubes = Wow!
« Reply #3 on: 6 Sep 2013, 02:14 pm »
glad that Roger's new tubes are working out fine. i just installed some new  JJ E34L's  that i got from roger. he did a custom match for my RM9SE. the ones that came with it were NOS Siemens. i was told by a very good friend, bobby at Merlin music systems to give them a try. they are his favorite tube and the EL34's his second. the 34L's are used in the ARS-Sonum amps that he uses at the audio shows. as i get more hrs on them i will report back.

roger thanks again for all your help!

rob.

Roger A. Modjeski

Re: New RAM tubes = Wow!
« Reply #4 on: 30 Sep 2013, 08:11 am »
Thanks, nice looking amp and great photos.