I thought I would re-fresh this article because as you do listening tests you learn more and I thought you might like to here the updates .The updates are in bold .
On one evening this week, I was at a friend’s house and we had some listening tests preamp valves in the V1 position in an amp. Here is a short summary of what we found.
The test amp was a Belcat and this is basically a clone of the Fender Blues Jr circuit.I have previously upgraded the output transformer to the same type as used in the Fender Blues Junior so this amp really does sound like a Fender. We used a Fender USA Telecaster 1952 re-issue as the test guitar. The neck pick-up on this guitar to my mind has a horrible muffled tone so we used the middle pick position and the bridge pick-up only. The amp had beed fitted with a JJ ECC83 Gold pins which is a richer sound than the standard JJ ECC83S
We tried the following valves from JJ Electronics :
- ECC83S Gold pins
- 5751
- 12AY7
- ECC803S ( long plate)
- Tung Sol 12Ax7.
The existing ECC83S with gold pins had a nice rich warm sound in the amp. So the challenge was could we improve it? The answer is yes ! The ECC803S from JJ was sonically much richer with a wider frequency range and even better mid range sound as compared to the ECC83S gold pins and that was good.
In this amp there was little to choose between the 5751 and the 12AY7. Both sounded nice but they just did not have the richness of the long plated ECC803S. However, when I did the same tests on a VOX Ac30 and Fender Deluxe Reverb, there was quite a difference. The 12AY7 created the thinner sound so reminiscent of the early 1960s pop songs and the 5751 made of a sonically pleasing clean sounding amp,
For the clean sound addicts, we thought in the Blues Jr the Tung Sol was the “thinnest” sound of all the valves we tested. Nice but lacking the richness we were looking for. I thought that there is little to choose between the Tung Sol or JJ standard product ( ECC83S and 12AX7) .
However when we tested in the Fender Deluse Reverb ( Silverface 1970) and the Vox AC30 CC1 the Tung Sol 12AX7 really showed us what it can do. The amp became rich toned and with a much more solid sound. For me the most surprising thing was the low microphonics especially in my Deluxe Reverb. It has always had the tendency to be very slightly microphonic. As valves /tubes age they become more microphonic so any improvement here was a real blessing. I can now turn the volume to 10 and tap the case and no microphonics. Tung Sol 12Ax7 are tested at the factory for microphonics and this is excellent. Well worth buying.
I was concerned that the longer plates of the ECC803S would result in increased microphonic in a a combo amp. JJ have put a lot of effort into the mechanical construction of this valve and it is certainly good enough to withstand the internal vibrations of a combo amp without the microphonic. Of course all valves have the risk of going microphonic when they get to the end of their life but that is the penalty we all pay for using lovely sounding valve amps. After all, valves are ancient technology and were being made a 100 years ago !!!
So the our vote went to the JJ ECC803S and the JJ ECC83S gold pins as the runner up
We have all these valves in our shop here on the site. You find them all by clicking here.
What is your experience with these preamp valves/tubes. We love to hear your comments and feedback. Just email us at info@valvetubeguitaramps.com
