Jolida 202a Tube Rolling Question 12ax7 12at7


Hi guys, a while back I purchased a jolida 202A to power my desktop speakers. I like the combination very much for accoustic/percussion music as nothing can quite beat it. However my $200 14 watt hong-kong amp is better for rock.
Before testing the other amp I thought it was simply a property of the speakers. But after putting the Jolida in my main setup I'm experiencing the same downfalls.

I don't really know how to pick tubes in order to get the qualities I'm looking for, so I was hoping that you guys could help out.

What I like about the sound now:
-Crisp details throughout the frequency spectrum
-Very speedy attack and decay on accoustic instruments

What I don't like:
-Very dry quality in the upper mids / lower HF
-Not enough tube bloom and warmth, too sterile
-The distortion at high power isn't like my little class A, (which just tends to get more blended and bloomy) but instead sounds rather grating in the high end and loses the bass.

Tubes I'm using right now:
4x JJ E34L's - Power
2x Electro-Harmonix 12ax7's in the preamp circuit
2x PhillipsECG 12AT7's as power drivers

I believe that the amp originally came with 4x 12AT7's though.
robxmccarthy

Showing 3 responses by ethanh

I strongly agree with the above posts recommending new 12AX7s. The EH12AX7s were the stock preamp tubes in my amp and replacing them definitely yielded the the most noticeable and profound changes in sound. I found the the Groove Tubes GT12AX7M to be a huge improvement in warmth, dimensionality, and overall listenability (really helped eliminate much of the hardness I previously heard in the upper frequencies). I think both the Groove Tubes and Tung-Sol reissues would provide you with a much nicer sound than your EH12AX7s provide, and would be a cost effective upgrade if NOS tubes are out of your budget.
Good luck.
Kehut, do you know if there is any difference in sound between the standard reissue Tung Sol 12AX7 and the gold plated "ECC803S" version you linked to? I understand some gold pinned tubes are pre-screened at the factory for lower noise but was curious if there is any noticeable difference in the tube's sonic "fingerprint," if you will. I'm interested to see how they might compare to the Groove Tubes in my system.