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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
montytx
138 posts
 
Nah, if it's a Blackburn production, it will have the Mullard characteristics. There are many Mullards with different labels. The main thing is to look for the characteristic code of B in the date codes.
pescolar
128 posts
 
Montytx, i have a questions from you.
What is the characteristic code of B in the data codes?
Btw,i have a pair of Mullard 12ax7 and Telefunken 12ax7 both branded Fisher.Which one should i used for my Jolida JD100 cd player ?, machine on it's way this week with a regular 12ax7 stock.
kehut's avatar
kehut
668 posts
 
I like the Ei 12AX7, but its not quite as good as either the Tele 803S or even the new Tung Sol ECC803S. Much smoother and better dynamics than the EH tube though.
montytx
138 posts
 
Mullard used the Philips code system on their tubes. The first 3 digits of the code, usually found on the lower part of the glass and very hard to see, are of little consequence. The 4th digit, often beginning right under the first 3, will designate the Philips factory that produced the tube. The "B" indicates the tube was made in the Blackburn factory and is a genuine Mullard, regardless of what the label says. The last 2 digits will indicate the year and month...sometimes another digit indicating the week that the tube was made.

The Telefunken tubes are more linear, pure and focused. The Mullards more warm, thick and texturally harmonic. If I were after all my gear could take, I would go with Telefunken. If I wanted to add a liitle more syrup and give up a little extension, I would go with Mullard.

I hope that helps a little. Personally, I like the reissue Tung-Sol so much I would never spend the extra money on a NOS Tele as they command silly money. Valvos, if the price is reasonable will get you most of the Telefunken sonics for a fraction of the cost.
robxmccarthy OP
10 posts
 
Hmm the Tung-Sol that I ordered was a standard new 12ax7. Is there really a big difference between that and the gold pin version? I just sort of assumed it would have better contacts. Hope I won't be disappointed.
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