Okay i promise i wont criticize horns and sets for a year , may be they ll let me inis an invite only
Okay i promise i wont criticize horns and sets for a year , may be they ll let me inis an invite only
Oh and Mike L. – I’m keeping in mind your Zeel 50 ohm preamp input requirements
Charles
Follow up:
Listened to the original cards for a few weeks and heard some great things. There were tweaks I had suggested and I gave my feedback to Charlie and Jeff. Initially, I could live with the cards and be perfectly content.... but, could they even get better? Reluctantly, I sent them back and went back to using my outboard pre.
Fast forward to the later part of February and I get a call from Charlie. They had taken some of my suggestions and reworked the cards. Supposedly, they were sounding even better. I awaited with baited breath.
Picture below: Looks like a totally different card. "Next Gen" even!
I installed the cards over the weekend and run my basic MRL tapes through the cards. (MRL #21J203 and 241-673-512-100) using the FM heads I had installed at the time. Man, what a transformation! These could even flat eq 20kHz !! No problems with phase or anything, measured by FFT. They were looking promising, to say the least. Jeff had said that the cards were decoupled someway from the VU meter, so all measurements were taken from my Fluke 115. Jeff had also sent some XLR and RCA break-out cables to use as well, for those that don't have their heads wired directly out.
I had a couple audiophile friends come over that wanted to listen. They were mightily impressed. Just for sh*ts and giggles, I told one of my friends to change the switch in the back of the machine to go from the cards to my outboard pre (Doshi). We were listening to a sample tape that I had made for one of the Axpona shows.
I COULD NOT BLINDLY TELL WHEN THE $20K OUTBOARD PRE WAS PLAYING!! It's as simple as that. I know Charlie can give you more particulars, but from what I heard, I'm keeping them.
I changed the headblock to stock Studer heads, and the results were even better.......
I swear, I don't know how they did it. Charlie already had one of the best sounding outboard pre's out there. Now, he's taking some of that know how and putting it in a smaller (and less expensive) format. You owe it to yourself if you have a Studer A8xx series deck. They are working on record cards as we speak. Contact Charlie (stellavox) for any questions and availability. I can guarantee the results.....
View attachment 90347
Follow up:
Listened to the original cards for a few weeks and heard some great things. There were tweaks I had suggested and I gave my feedback to Charlie and Jeff. Initially, I could live with the cards and be perfectly content.... but, could they even get better? Reluctantly, I sent them back and went back to using my outboard pre.
Fast forward to the later part of February and I get a call from Charlie. They had taken some of my suggestions and reworked the cards. Supposedly, they were sounding even better. I awaited with baited breath.
Picture below: Looks like a totally different card. "Next Gen" even!
I installed the cards over the weekend and run my basic MRL tapes through the cards. (MRL #21J203 and 241-673-512-100) using the FM heads I had installed at the time. Man, what a transformation! These could even flat eq 20kHz !! No problems with phase or anything, measured by FFT. They were looking promising, to say the least. Jeff had said that the cards were decoupled someway from the VU meter, so all measurements were taken from my Fluke 115. Jeff had also sent some XLR and RCA break-out cables to use as well, for those that don't have their heads wired directly out.
I had a couple audiophile friends come over that wanted to listen. They were mightily impressed. Just for sh*ts and giggles, I told one of my friends to change the switch in the back of the machine to go from the cards to my outboard pre (Doshi). We were listening to a sample tape that I had made for one of the Axpona shows.
I COULD NOT BLINDLY TELL WHEN THE $20K OUTBOARD PRE WAS PLAYING!! It's as simple as that. I know Charlie can give you more particulars, but from what I heard, I'm keeping them.
I changed the headblock to stock Studer heads, and the results were even better.......
I swear, I don't know how they did it. Charlie already had one of the best sounding outboard pre's out there. Now, he's taking some of that know how and putting it in a smaller (and less expensive) format. You owe it to yourself if you have a Studer A8xx series deck. They are working on record cards as we speak. Contact Charlie (stellavox) for any questions and availability. I can guarantee the results.....
View attachment 90347
Yes. What we found after extensive measurements on the A80 is that repro cable pickup Itself contributes no meaningful contribution to the actual noise floor with well-designed on-card preamplifier (including RFI suppression); effectively all the “noise” pickup is directly thru the repro head gaps themselves, captan motor dominant even with the double-shielded 30 ips capstan motor. In addition, the repro gap / channel closest the baseplate (and capstan motor) has a bit higher A-wtd noise (About +1dB).Did you consider the possibility of building an in- head preamp for the A80's , as ATAE had done in their models?
Yes. What we found after extensive measurements on the A80 is that repro cable pickup Itself contributes no meaningful contribution to the actual noise floor with well-designed on-card preamplifier (including RFI suppression); effectively all the “noise” pickup is directly thru the repro head gaps themselves, captan motor dominant even with the double-shielded 30 ips capstan motor. In addition, the repro gap / channel closest the baseplate (and capstan motor) has a bit higher A-wtd noise (About +1dB).
With our new A80 Repro card the A-wtd noise floor is within 1 dB with capstan and reel motors running and tape moving, and all motors stopped, on each chan, and Represents approximately 80 dB SNR A-wtd below 350nW/m fluxivity in the deck.
The NE5532a opamp used in the Studer A810/820 headblock is spec’red at 5nv/root Hz at 1 kHz, or +8.5 dB higher than our A80 repro card Preamp, and +16 dB higher at 30 Hz than our press; in addition the NE5532a has 1000x higher bias current flowing through the head at 200nA typical, leading to some head magnetization and additional nonlinear distortion.
Consequently, with the A80 there is no benefit to be had with a headblock preamp stage over the one built on our NextGen A80 Card.
In the case A810/A820 the electrical situation is exactly the same. But the smaller form factor of the repro card presents difficulty packaging all the discrete circuitry unless surface Mount is used so we consider placing the preamp stage back in the headblock.
thx for your inquiry.
Jeff
Sorry to say not at this time, as our NextGen A80 card is new and we do not yet have a distributor in the EC.Thanks for your extensive and extremely well documented answer. Can you ship your cards from an EC country?
Thanks very much for your interest and valuable feedback; you are absolutely correct regarding footprint taken up by the M-DACS and the associated NE5532A I/V buffer(s) on each; we will use the identical small multi-turn Bourns trimpots as used on our NextGen A80 repro card that Bruce Brown reviewed most favorably.I’m likely interested in 1 or 2 sets of the A820 cards. From my perspective, the closer they can be to a direct plug-in replacement, the better.
The convenience of having multiple EQs and speeds easily available is a really nice feature which ideally would be maintained. However I presume that the digital select logic and multiplying DACs take up more board space than multiple sets of trimpots and a selector switch which is probably why you are thinking of going that direction. Plus doubtless it simplifies things. So if that capability has to be dropped, in favor of a selector switch on the card, it probably wouldn’t be a deal killer for me.
My strong preference would be to not simply bypass the headblock preamp. And if a replacement is created (likely required to get the quality you are after), it would be very nice if it was compatible with the current one so that headblocks are interchangeable between machines with the existing and your new reproduce amplifiers.
I presume it doesn’t make sense to also create replacement Line Amplifier cards too? While that would give you twice as much board space to work with, it probably also means that there’d be lots of additional stuff you’d have to interface with. I’m guessing that trade off doesn’t make sense?
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