ECC81 preamp
Posted: Sat 12/10/11 10:14 am
For some time I have had a box of old valves sitting around left from my ham radio efforts. They were inherited from my father who was a serious electronics hobbyist. I have no idea of their age but I have had the box since the early 70s.
Among the stock were some ECC81s which I had been meaning to try out. So I picked one of each make a Mazda and a Mullard to try in my Normal channel which has a paralleled input and a single input.
I was expecting less gain and more headroom, which has been provided by both valves. But I am astonished not just at the difference in tone from the two ECC83s I have previously used (JJ and a Sovtek). But also between the two old makes.
The Mullard is soft and easy going but when pushed it has a gorgeous rounded distortion. The Mazda is similar but has a sharp edge to it.
A further benefit from the ECC81 is the variation gained from using the VVR on that channel. From clean warm tones at a good volume (high voltage) to smooth distortion at lower voltages. But the quality deteriorates sooner than with the ECC83s.
I have to confess to having been sceptical about the amount of real difference between old stock and recent production. Looks like I will have to review that position. But I have no intention of swapping out the trem channel ECC83 for an ECC81. I will have to dig deep for a Mullard I guess.
Dd
Among the stock were some ECC81s which I had been meaning to try out. So I picked one of each make a Mazda and a Mullard to try in my Normal channel which has a paralleled input and a single input.
I was expecting less gain and more headroom, which has been provided by both valves. But I am astonished not just at the difference in tone from the two ECC83s I have previously used (JJ and a Sovtek). But also between the two old makes.
The Mullard is soft and easy going but when pushed it has a gorgeous rounded distortion. The Mazda is similar but has a sharp edge to it.
A further benefit from the ECC81 is the variation gained from using the VVR on that channel. From clean warm tones at a good volume (high voltage) to smooth distortion at lower voltages. But the quality deteriorates sooner than with the ECC83s.
I have to confess to having been sceptical about the amount of real difference between old stock and recent production. Looks like I will have to review that position. But I have no intention of swapping out the trem channel ECC83 for an ECC81. I will have to dig deep for a Mullard I guess.
Dd