Wow, sorry to hear that you find "maybe they will sound different, maybe they won't" to be relatively aggressive. I really AM interested to find out what others think about the sound of the M2x when the five different input stages are installed. Wouldn't it be extremely cool to discover that one of the (gasp!) integrated circuit input stages, sounds better to you than the original Nelson Pass input stage using discrete JFETs? On the other hand wouldn't it be fascinating, to find out that you don't hear any difference between several of the IPSs, despite their wild dissimilarity? I myself find it exhilarating, in either case.
I offer my best wishes for huge success with your M2x amplifier build!
I offer my best wishes for huge success with your M2x amplifier build!
I'll have to apologize for Mark, he sometimes comes across in text as kinda snarky, but for real is one of the nicest, warmest, smartest and friendliest guys I know. Tone is pretty hard to type, and can come across differently than intended.
Anyway, the point Mark was trying to make isn't that all solid state sounds alike, I don't think anybody is going to argue that, but rather if the sonics of the transformer/autoformer is going to hide any differences that the various input stages impart. I haven't yet had a chance to compare anything even though I do have a few of the input built. I am genuinely interested in what people think as they listen to the different topologies.
Anyway, the point Mark was trying to make isn't that all solid state sounds alike, I don't think anybody is going to argue that, but rather if the sonics of the transformer/autoformer is going to hide any differences that the various input stages impart. I haven't yet had a chance to compare anything even though I do have a few of the input built. I am genuinely interested in what people think as they listen to the different topologies.
6L6 doesn't have to apologize at all.
People like Mark, who make such considerable donations of their time and expertise for the benefit of the multitude should be afforded much consideration and leeway when interpreting their posting.
On the other hand my beard needs to get significantly longer before I fully understand what ZM posts.
)
People like Mark, who make such considerable donations of their time and expertise for the benefit of the multitude should be afforded much consideration and leeway when interpreting their posting.
On the other hand my beard needs to get significantly longer before I fully understand what ZM posts.
)
And 6L6 & I have each made a prediction about what most M2x listeners will say when asked, "Which one sounds best, to you?" . Predictions which we may or may not reveal (depending on how wrong we were), in a few months after people have had a chance to build and listen to their M2x.
edit- predictions based only upon studying the schematics and interviewing the designer. Neither of us "peeked" by listening to all five before predicting.
edit- predictions based only upon studying the schematics and interviewing the designer. Neither of us "peeked" by listening to all five before predicting.
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6L6 & MJ,
I am greatly looking forward to building each and every iteration starting with the Ishikawa as a reference point. Thanks again. I don’t anticipate the Edcor autoformer to be in stock at the diyaudio store anytime soon (although I recall that Mr.Pass was going to forward a stash he had), so I might as well order since Edcor has such long wait times.
Thanks again for providing us with 6 different varieties of amplifier for the price of one!
Anand.
I am greatly looking forward to building each and every iteration starting with the Ishikawa as a reference point. Thanks again. I don’t anticipate the Edcor autoformer to be in stock at the diyaudio store anytime soon (although I recall that Mr.Pass was going to forward a stash he had), so I might as well order since Edcor has such long wait times.
Thanks again for providing us with 6 different varieties of amplifier for the price of one!
Anand.
Ordered my Edcors Saturday 5/19 and they shipped today 5/23. Speedy! Was expecting weeks, not days. Also, PCBs received and look really great.
BK
Tucson has the 2nd fewest parts to order, and to solder, and to avoid screwing up.
Ishikawa has even fewer, if you are somehow able to get the Toshiba or Linear Audio JFETs.
The lowest distortion opamp IC in the entire world, fits just fine on Tucson. It uses the SMD option. 6L6 and I have both soldered that one onto a couple Tucson boards. We're ready.
Ishikawa has even fewer, if you are somehow able to get the Toshiba or Linear Audio JFETs.
The lowest distortion opamp IC in the entire world, fits just fine on Tucson. It uses the SMD option. 6L6 and I have both soldered that one onto a couple Tucson boards. We're ready.
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This seller of genuine Toshiba Jfets has bee verified by Nelson, they are real parts.
Toshiba 2SJ74 + 2SK170 LAB MATCHED PAIR 0.03mA AND 4mV (7ma Idss Range) | eBay
So for the time being we have a source for Jfets. Get 'em while you can.
Toshiba 2SJ74 + 2SK170 LAB MATCHED PAIR 0.03mA AND 4mV (7ma Idss Range) | eBay
So for the time being we have a source for Jfets. Get 'em while you can.
Assuming the production boards fit in a 2U 300mm long minidissipante case...
Using two Meanwell 24V SMPS, you could run a couple of Juma CapX mounted on the inside of the back of the case to drop the supply rails to ~19V (If necessary add heatsinks on the rear of the case. This results in 50W per channel dissipation at ~1.3A idle current. It should all work in a 300mm deep version of the ACA...
Am I missing anything?
Using two Meanwell 24V SMPS, you could run a couple of Juma CapX mounted on the inside of the back of the case to drop the supply rails to ~19V (If necessary add heatsinks on the rear of the case. This results in 50W per channel dissipation at ~1.3A idle current. It should all work in a 300mm deep version of the ACA...
Am I missing anything?
