Bronal Posted June 12, 2014 Posted June 12, 2014 I'm about to take delivery of another Tram 2 preamp. Unlike my current Tram, which uses 45s (EMLs)the new one is set up for 2A3s. I did try 2A3s initially myself, but found the ones I bought (TJ Full Music) to be highly microphonic. Can anyone recommend 2A3s that aren't or are minimally microphonic? Current production valves preferred - I don't want to get into NOS.
Steve M Posted June 13, 2014 Posted June 13, 2014 (edited) Bronal, Microphonics and noise in all DHT preamps is something you have to live with. The Tram is particularly bad in this way because both power supply and preamp section is crammed into one small chassis. The Tram that I had used RCA 2A3 and it was very quiet, I tried it with about six different pairs of 45 and all were noisy, tube rush noises, severe hum and microphonics with these tubes. You do have to put a copper or steel cage/box around the output tubes to control stray electromagnetic fields and to reduce hum. The Tram is a somewhat temperamental beast, but sounds excellent! If I was not using Supratek, the Tram would be my main preamplifier. The sound of it is extremely vivid and clear, good tone and accurate all round. My Tram was not modded and fiddled with and is reliabe, it is with a family member now and continues to impress him beating all others he has tried. It is a pity that these great sounding preamps are no longer made and that it's designers (including Thorsten Loesch of AMR) did not continue to perfect them, as the Tram2 is a bit of a world-beater. Cheers, Steve. Edited June 13, 2014 by Steve M
gavtron Posted June 13, 2014 Posted June 13, 2014 (edited) The Sophia Princess 2a3's I was using in the DNA Stratus amp seemed pretty good. Still a few minutes warm up before all the tiny "dings" subsided.. Edited June 13, 2014 by gavtron
Bronal Posted June 13, 2014 Author Posted June 13, 2014 Bronal, Microphonics and noise in all DHT preamps is something you have to live with. The Tram is particularly bad in this way because both power supply and preamp section is crammed into one small chassis. The Tram that I had used RCA 2A3 and it was very quiet, I tried it with about six different pairs of 45 and all were noisy, tube rush noises, severe hum and microphonics with these tubes. You do have to put a copper or steel cage/box around the output tubes to control stray electromagnetic fields and to reduce hum. The Tram is a somewhat temperamental beast, but sounds excellent! If I was not using Supratek, the Tram would be my main preamplifier. The sound of it is extremely vivid and clear, good tone and accurate all round. My Tram was not modded and fiddled with and is reliabe, it is with a family member now and continues to impress him beating all others he has tried. It is a pity that these great sounding preamps are no longer made and that it's designers (including Thorsten Loesch of AMR) did not continue to perfect them, as the Tram2 is a bit of a world-beater. Cheers, Steve. Thanks Steve. The EML 45s in my current Tram are very quiet (I have 99dB sensitive speakers) and non-microphonic (after about 10 minutes, when warmed up). I've tried NOS 45s as well but I inevitably got pops and whispering - what can you expect with valves over 60 years old? I notice that EML make 2A3s as well. I'll probably try Sovteks to start off with (don't laugh, they're virtually bullet proof and very reliable), but if 2A3s don't work out I'll go back to 45s. I'm surprised some enterprising manufacturer hasn't licensed the rights to the Tram from DIY HiFi Supply and re-engineered it as you suggest.
Bronal Posted June 13, 2014 Author Posted June 13, 2014 The Sophia Princess 2a3's I was using in the DNA Stratus amp seemed pretty good. Still a few minutes warm up before all the tiny "dings" subsided.. My understanding is that Sophia valves are made by TJ.
Recommended Posts