Location: Lincolnshire
Posts: 47
I'm Zander.
Thanks, so no JFETs involved in MM, so I am only “hearing” the difference (or not ) in the valves.
My ears are the wrong colour I think, skin tone rather than golden.
I have an EI ECC83 and Siemens PCC88s fitted, and it is still very good, possibly a tiny bit less good than a real TFK ECC83.
I think I am almost at a point where I am going to stop worrying, and just chuck something I like in there, and be done with it.
Kevin
Too busy enjoying the music....
European loan coordinator for Graham Slee HiFi system components..
Location: Lincolnshire
Posts: 47
I'm Zander.
I would be interested to know if you are listening to the JFets or valves or probably both when in MC use and in which case are the JFets contributing more to the sound rather than the valves?
But if only using MM then I suppose the BB3 can be switched to work valve only?
I have a huge stock of valves here now after years of collecting and even now I am after more! They do certainly make a difference to the sound but I think not as huge as folk imagine. I recently had a huge bake off with 12BH7a valves in my line stage with about 8 different valves from RCA, Westinghouse, Brimar, GE, JJ, Electro Harmonix, Sylvania and Philips in my line stage and I got frustrated because I know not all of them were measuring full power and some were very old and some still almost new. Did my nut in as I did here strengths and weaknesses with all of them but I really only found one that seemed to tick nearly all the boxes.
Differences were small in many cases and I had to choose one I could live with day to day.
You would not have this problem with SS!
Main system : VPI Scout 1.1 / JMW 9T / 2M Black / Croft 25R+ / Croft 7 / Heco Celan GT 702
Second System : Goldring Lenco GL75 / AT95EX / Pioneer SX590 / Spendor SP2
I agree. The differences are small.
With the Siemens PCC88 fitted, I would struggle to tell which ECC83 was fitted at any one time.
They may be more pronounced with a MC cartridge fitted. I shall have to try.
Kevin
Too busy enjoying the music....
European loan coordinator for Graham Slee HiFi system components..
Location: Lincolnshire
Posts: 47
I'm Zander.
I asked, i think you can ask him directly as you know him - he said so.
"Hi Zander!
Busy today? lol
The JFET is being used as an amplifier. It is creating gain by amplifying the signal it receives from the MC cartridge. The JFET will be higher in SNR, lower in distortion and lower THD+N than any of the valves in the phonostage, and that means it's influence is far less than the valve stage itself. The amplified signal from the JFET (MM Signal level now for simplicity) is then fed into the rest of the circuitry which is responsible for RIAA equalisation and so-on.
Are you listening to the Jfet?
Well, Any device at the front end of a MC phonostage is effectively responsible for what the rest of the circuit sees, as it is adding gain. Be that via JFets, SUTs, Opamps etc, they all take 100% of the signal and amplify it BEFORE the phonostage circuitry gets it. Unless you use MM, there is simply no way to use a MC cartridge without some form of amplification device on the front end.
With Jfets and opamps, the effect of them is simple, the better they do their job, the less audible they become. An opamp with THD+N of 0.00024% is not going to have any negative effect on the THD+N figure you would get from a MM valve Phonostage, as that figure would likely swamp a quality Jfet or Opamp. My honest opinion is that the Jfet that we use for the BB3 is the 3rd most inaudible gain device we have heard, the 2nd being the JFET in the BBU (Higher grade JFET), and top of the pile is the Opamp we use in the Avalon Phonostage. IF anyone thinks the Jfet is more influential to sound than a valve, they would need to provide some never before seen measurements!
Have a look here:
https://www.vtadiy.com/home/tube-amp...be-comparison/
Oh, BTW....tell these "forum people" to email me. I don't bite! lol and say Hi from me.
Oliver"
Oh, we know Oliver…
I was just interested to see if there were any sensibly priced ECC83 or PCC88 I may have overlooked.
Kevin
Too busy enjoying the music....
European loan coordinator for Graham Slee HiFi system components..