Hehe! Remember thathe transformers affect the distortion profile and it can be tweaked. So consider a slightly warmed up Onetics. Sweet, like red velvet😀
I did run them both in for 1/2 hour before, but then swapped in the other one, which was cold. The amp itself had been running more of less continuously for 30 hours or so to get it's muscles stretched out.
My observations are not conclusive, and the Onetics certainly have not had a lot of run in time on my system.
My lack of zen pots may expose some less than preferable distortion curves on JFETs.
I will put them in when I can get some software running into the sound card. I've got some scope meters for it that Generg recommended - so I am almost there, just got to get the software to co-operate. And I am not so good at that.
My observations are not conclusive, and the Onetics certainly have not had a lot of run in time on my system.
My lack of zen pots may expose some less than preferable distortion curves on JFETs.
I will put them in when I can get some software running into the sound card. I've got some scope meters for it that Generg recommended - so I am almost there, just got to get the software to co-operate. And I am not so good at that.
I have both. It's a little harder to drag my mac-mini into basement, so I am considering just measuring the amp near the mac - the mac is my computer audio output - so all in proximity.
when using two SemiSouth even with matched Vgs I dare to say...
you cannot say how the distortion spectra looks like, more k2 or k2 and k3 at the same level it is uncertain. In my eyes you have to measure and .... be surprised....😀
you cannot say how the distortion spectra looks like, more k2 or k2 and k3 at the same level it is uncertain. In my eyes you have to measure and .... be surprised....😀
Agreed, although the ears do give hints. For me, second always comes with greater vertical space. Very triodish in nature
Brother has tub amp with pentode/triode switch and very easy to see difference when it comes at flip of a switch.
Merry Christmas to you, Generg!
Merry Christmas to you, Generg!
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Okay a few thoughts - GB ends this sunday. So I need payment by then, don't count on me ordering extra boards. It seems when I do, they have a way of dissapearing quickly once I actually have them on hand.
The boards will be a bit smaller than some of the prototype pictures to work better with the diyaudiostore amp chassis (at least the big one). 6 speed has been doing scaled model printouts cutout and fit to the chassis.
Did some more listening to the F6. - The Figure 13 - buffered setup, without any zen pots, or any degeneration. Trying to keep it simple for now. Give me too many variables to control - and I go mad science and cannot be sure of anything.
Funny how it sounds so controlled and meaty when hooked up to my Fostex FF125WK - these are now my test bench speakers. They sounds really good with this amp, but only when I really crank it up. Excellent soundstage. I really dont like these fostex for a small speaker in bass reflex box. I like the CHR-70's the best in my collection of small full rangers.
Hooked up to lowthers in main system - now this is what I remember hearing from the real J2 I heard - a bit liquid and smooth.
Even my wife says it's a tamer amplifier than others. But I don't find it too laid back.
I am trying to get distortion spectra on the amp with some help from Generg.
The transformers all sound 'different'. But I would say that the Jensens characteristics are the most unique. Can't explain why. Not sure I like it the best either. But it brings quite a unique tone and presence to the setup. The Onetics and Cinemag are more similar in they would appear to me to be a little bolder sounding, and possibly a little more neutral in tone, but still have a little bit of liquid and smoothness to it. The Onetics sounded bad until I had about 48 hours of burn-in on them.
The boards will be a bit smaller than some of the prototype pictures to work better with the diyaudiostore amp chassis (at least the big one). 6 speed has been doing scaled model printouts cutout and fit to the chassis.
Did some more listening to the F6. - The Figure 13 - buffered setup, without any zen pots, or any degeneration. Trying to keep it simple for now. Give me too many variables to control - and I go mad science and cannot be sure of anything.
Funny how it sounds so controlled and meaty when hooked up to my Fostex FF125WK - these are now my test bench speakers. They sounds really good with this amp, but only when I really crank it up. Excellent soundstage. I really dont like these fostex for a small speaker in bass reflex box. I like the CHR-70's the best in my collection of small full rangers.
Hooked up to lowthers in main system - now this is what I remember hearing from the real J2 I heard - a bit liquid and smooth.
Even my wife says it's a tamer amplifier than others. But I don't find it too laid back.
I am trying to get distortion spectra on the amp with some help from Generg.
The transformers all sound 'different'. But I would say that the Jensens characteristics are the most unique. Can't explain why. Not sure I like it the best either. But it brings quite a unique tone and presence to the setup. The Onetics and Cinemag are more similar in they would appear to me to be a little bolder sounding, and possibly a little more neutral in tone, but still have a little bit of liquid and smoothness to it. The Onetics sounded bad until I had about 48 hours of burn-in on them.
Teabag,
Thanks for the above update. Appreciate the hard work you put in.
Is there any update on the R100? Will there be some form of GB for matched pairs from Semisouthfan?
Thanks for the above update. Appreciate the hard work you put in.
Is there any update on the R100? Will there be some form of GB for matched pairs from Semisouthfan?
Regarding SemiSouth's here is the delimma.
The R100's @ current pricing is 50.00 each, buying a bunch of them will end up for people having to pay more, a matching fee and paypal the price climbs quick. I am not sure that you guys are willing to pay for that. Loose a couple in the mail uninsured and everyone is pissed.
I am looking into buying some 'B' stock stuff that did not meet all parameters of original spec sheet. This is much what they did with the R100A's AFIAK.
I've added everyone who has asked to the spreadsheet.
The R100's @ current pricing is 50.00 each, buying a bunch of them will end up for people having to pay more, a matching fee and paypal the price climbs quick. I am not sure that you guys are willing to pay for that. Loose a couple in the mail uninsured and everyone is pissed.
I am looking into buying some 'B' stock stuff that did not meet all parameters of original spec sheet. This is much what they did with the R100A's AFIAK.
I've added everyone who has asked to the spreadsheet.
okay, I think some R125's will be available (the original) these are considered A-stock, except they have been burned in and tested extensively. So they apparently have not appeared as new. I have not seen them yet. But I will buy some.
The R100's will be "B" stock. Some that did not meet full testing spec. Similiar to an R100A to a degree. I don't have the full test equipment (particularily a curve tracer) to look at all their datasheet variables to test - but I am seeing about borrowing one from someone if they have it.
The R100's will be "B" stock. Some that did not meet full testing spec. Similiar to an R100A to a degree. I don't have the full test equipment (particularily a curve tracer) to look at all their datasheet variables to test - but I am seeing about borrowing one from someone if they have it.
I need to amend my last comments, as I did not understand all my previous dialogue with SemiSouthFan.
All product will be marked as E120R125 - the original SS parts used in first J2.
I am getting two different batches of them.
One batch is one's that have been under long term extensive testing, and of coursed passed. Cosmetically you can tell this, some are marked etc.
The second batch are one's that did not meet original Spec of AC Gate voltage of -15 to +15, and are -10V to +15. These are more similiar to the discounted R100A's that were 'designated for Audio' in previous productions. All of these should be fine for audio applications.
Combined there will be about 40 pairs available, assuming all goes as planned. No pricing is available yet. But will likely beat SemiSouthFan's pricing for NOS umatched stock. Sign up sheet is in my signature.
All product will be marked as E120R125 - the original SS parts used in first J2.
I am getting two different batches of them.
One batch is one's that have been under long term extensive testing, and of coursed passed. Cosmetically you can tell this, some are marked etc.
The second batch are one's that did not meet original Spec of AC Gate voltage of -15 to +15, and are -10V to +15. These are more similiar to the discounted R100A's that were 'designated for Audio' in previous productions. All of these should be fine for audio applications.
Combined there will be about 40 pairs available, assuming all goes as planned. No pricing is available yet. But will likely beat SemiSouthFan's pricing for NOS umatched stock. Sign up sheet is in my signature.
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