Yes, back then it was basically just a hobby for people who loved tape and tape machines, as quality high speed pre-recorded material simply did not exist. This was the reason I missed the early part of the current wave. At that point my park was down to just one very nice Otari 5050 Mk III, sitting idle. So kudos to those people who created the wave.
AK (hot rodded) Ampex ATR-102's w/MR-70 Preamps replaces my Studers.
- Thread starter Mike Lavigne
- Start date
Mike,
Did you try using the MR70 preamplfiers with your A820's?
As far as I could see the MR70 is a tube preamplifier with a head loading transformer in the input, probably to improve the signal to noise ratio - an interesting approach.
Did you try using the MR70 preamplfiers with your A820's?
As far as I could see the MR70 is a tube preamplifier with a head loading transformer in the input, probably to improve the signal to noise ratio - an interesting approach.
no. in real world terms, a nice, minty, Ampex ATR-102 is worth less than a nice, minty Studer A-820. and the ATR's have been (up to this time) 'gettable' to acquire. ATR-102 parts and pieces as well as the simpler operating systems lend themselves to the refurbishing process. so it is much less expensive to match the ATR with the MR-70 than the Studer A-820 for a number or reasons. doubtful i could have afforded it.
Ki Choi did buy 4 MR-70 preamps with the intention of doing what you ask about. but decided to sell the MR-70 preamps to AK instead.
i really don't know if there is any technical reason you can't match the MR-70 to the A-820. i assume the Flux Magnetic heads for the MR 70 would also work in the A-820 head block. but i've not heard of it actually being done. it's possible that the degree of tweaking required to get real synergy between those two might not be as easy as the ATR....but maybe it's easier. i don't personally know.
i only know that the MR-70 head spec is unique. when i purchased my ATR-102/MR-70 in September, Flux Magnetic only made 1/2" heads for it. now AK has been able to get them to make a 1/4" set of heads for the MR-70. i intend to have AK build me another set of MR-70 preamps for 1/4" heads that i can swap out so i can play all my tapes on the MR-70 pre's. but that is not yet 100% nailed down.
Greg Orton (Flux Magnetics) has built both 1/2" and 1/4" heads for my different ATR 1092 head blocks over the years. Last time I talked with Greg, he was thinking about retiring. That is true of fellow Ampex alum John French who has been the go to person for head relapping. Unfortunately, we're not the only ones getting old. 
Larry
Larry
Larry , et al - I want to make sure people know that Dan Labrie, the former Lead Technician at ATR Service Corp, is now operating independently out of Philadelphia, PA as Myriad Magnetic and is rebuilding ATRs as he did when working for Bette during the previous decade. He has not stopped this work since leaving the company last year.
Dan has stock of ATR-100s available for refurbishment, configurable to your needs, and works directly with Flux Magnetics for new heads. He can be reached through his website at Myriad Magnetic, directly at dan@myriadmagnetic.com, or via Instagram @myriadmagnetic for pricing and lead time information. While Dan now also works on other pro tape machines, his core focus of work remains the repair and refurbishment of ATR-100s.
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This is such a good news, and so close to me, too! Thank you so much!
What is the nuvistor being used in the MR70? I think I still have a box with spare 6CW4's that were used in conrad johnson early phono preamplifiers.
from post #4 in this thread.....since my MR-70's are not set up to record/erase, and are not using the original transport, maybe not all of these Nuvistors are needed or resident. i could ask AK about that.
Tube complement: 6 x 7587 Nuvistors, 12 x 7895 Nuvistors (for each channel). 4 of each type for bias / erase oscillator / Bias / erase: Plug-in master oscillator on transport. 150 kHz frequency / Erasure: a mid frequency signal recorded at peak record level will be reduced by at least 68dB when erased / Channel separation: less than 0.5% / Even order distortion: 2nd harmonic distortion of a 500Hz signal recorded at peak record level is less than 0.5% / Start time: tape within ± 0.2% of nominal speed in 0.5 seconds.
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Nuvistors enjoyed brief popularity, but fell out of favor quickly. Many tube designers prefer to stay away from them. They had some advantage in things such as oscilloscopes, due to their low parasitic capacitance, but in my view there are better tubes available.
Thanks, good to know about Dan's new business. He's a good guy. Larry
Congratulations Mike,
Regarding the "4 digit numeric" nuvistors used in the electronics. A friend had one (maybe 2) 70's back 30 years ago. Got a bunch of spare tubes for them. Checked them on his tester (Hickock as I remember) and found a whole bunch of them tested bad - threw them out. Then found out (somehow) that the testers setup instructions for that tube were wrong! Retested a few tubes that he didn't trash and they checked FINE. Oh well
Charles
Regarding the "4 digit numeric" nuvistors used in the electronics. A friend had one (maybe 2) 70's back 30 years ago. Got a bunch of spare tubes for them. Checked them on his tester (Hickock as I remember) and found a whole bunch of them tested bad - threw them out. Then found out (somehow) that the testers setup instructions for that tube were wrong! Retested a few tubes that he didn't trash and they checked FINE. Oh well
Charles
thanks Charles.
as you know i'm no techie, so know nothing about the Nuvistors. AK (my friend Andrew) told me he has acquired 'many' Nuvistors' and had found that many he purchased did not pass his tests, but plenty did. he assured me he had plenty to support my 'habit'
for the foreseeable future..
(...) AK (my friend Andrew) told me he has acquired 'many' Nuvistors' and had found that many he purchased did not pass his tests, but plenty did. he assured me he had plenty to support my 'habit'
The 7587 nuvistor is really common - you can find retailers having thousands in storage. In fact, when I needed 6CW4's they were inexpensive but I had to test them for noise - about half were too noisy for a phono pre-preamplifier.
was traveling last weekend, and today was the first really free day in three weeks. a light rain was falling, around 40 degrees f, and great day to just kick back. next weekend is the Super Bowl.......so today was an all-analog day, played all three turntables, 10+ Lp's, and both tapes decks, 6-7 tapes.....maybe 10 reels.....and still going with the turntables.
starting to sort things out in my mind how the new 'AK' Ampex decks and MR-70 compared to my vinyl lays out.
my improvements this past year in my vinyl has really put the pressure on my tape to be better, and it's delivering. EMIA phono + SUT's, Primary Control FCL arm, the DaVa Ref cartridge, the 3 anti static devices, the dongle added to the LFD phono cables + the better interconnect from the EMIA to the dart pre......it all adds up. some little things and some bigger things. that's a lot of added vinyl firepower.
the new 'AK' level of tape performance has moved the needle. no doubt. it was as enjoyable a day of listening all around as i have had, and it's not finished yet. where my mind is at the moment, is not really thinking about what is better or best but how i'm getting the most involving music connection from every recording. every one an experience to savor, with my head and heart. just living in the moment, and see how i feel about it later.
starting to sort things out in my mind how the new 'AK' Ampex decks and MR-70 compared to my vinyl lays out.
my improvements this past year in my vinyl has really put the pressure on my tape to be better, and it's delivering. EMIA phono + SUT's, Primary Control FCL arm, the DaVa Ref cartridge, the 3 anti static devices, the dongle added to the LFD phono cables + the better interconnect from the EMIA to the dart pre......it all adds up. some little things and some bigger things. that's a lot of added vinyl firepower.
the new 'AK' level of tape performance has moved the needle. no doubt. it was as enjoyable a day of listening all around as i have had, and it's not finished yet. where my mind is at the moment, is not really thinking about what is better or best but how i'm getting the most involving music connection from every recording. every one an experience to savor, with my head and heart. just living in the moment, and see how i feel about it later.
Mike:
Sorry to burst your bubble, but magnitude frequency response - in isolation - that is, without phase- or Group Delay- measurements vs frequency, or better yet full time domain impulse response and coherence function measurements along with the usual THD/IM distortion and SNR - is NOT particularly useful or meaningfull in characterizing exactly how accurate any tape reproducer (or ANY Audio Electronics) really performs and sounds.
NestGen publishes complete Time Domain Impulse Response, Group Delay, Coherence Function, THD versus fluxivity and other critical measurements on our re-defining NextGen Studer A80R/C record and repro electronics - and soon standalone outboard electronics.
https://www.whatsbestforum.com/threads/new-repro-cards.33585/page-6
https://www.whatsbestforum.com/threads/new-record-cards.35607/
Where are the equivilent data for the AK modified ATR-102/MR-70? if sounds as good as you claim, I would certainly like to see the data supporting such a conclusion. For now, I will continue to claim, backed up by both extensive listening tests as well as the science, that our NextGen record and repro electronics for the Studer A80R/C is currently the most accurate analog recorder in the world, and by a very considerable margin.
Regards,
Jeff Polan
Sorry to burst your bubble, but magnitude frequency response - in isolation - that is, without phase- or Group Delay- measurements vs frequency, or better yet full time domain impulse response and coherence function measurements along with the usual THD/IM distortion and SNR - is NOT particularly useful or meaningfull in characterizing exactly how accurate any tape reproducer (or ANY Audio Electronics) really performs and sounds.
NestGen publishes complete Time Domain Impulse Response, Group Delay, Coherence Function, THD versus fluxivity and other critical measurements on our re-defining NextGen Studer A80R/C record and repro electronics - and soon standalone outboard electronics.
https://www.whatsbestforum.com/threads/new-repro-cards.33585/page-6
https://www.whatsbestforum.com/threads/new-record-cards.35607/
Where are the equivilent data for the AK modified ATR-102/MR-70? if sounds as good as you claim, I would certainly like to see the data supporting such a conclusion. For now, I will continue to claim, backed up by both extensive listening tests as well as the science, that our NextGen record and repro electronics for the Studer A80R/C is currently the most accurate analog recorder in the world, and by a very considerable margin.
Regards,
Jeff Polan
Jeff, and what if it does not support the perceived good sound? I am not speaking of your design, of course, as I am not privy to its details, but the landscape is littered with the bodies claiming better measured performance, but rejected by the customers. Remember those amps with .0001% THD?
As a designer, I admire your rather impressive numbers.
As a designer, I admire your rather impressive numbers.
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open your own thread and sell your products. or maybe have one of your customers come into this thread and tell us what they hear.
but my 2 cents is that it's bad form for a manufacturer to jump into a thread selling their products. and knocking other products. you could have a better mouse-trap. someone has to listen first and tell us.
"where is the equivalent data?".......sure you got the right forum? data is for after you like it.
I can vouch for Jeff´s claim and testify that the new repro boards from Jeff Polan and Charles King elevated the performance of my Studer A80RC 2T 1/4 to unbelievable level
I have recommended the boards to an old time friend of mine in Sweden who´s over the moon...he also already had the MTSL cards and also a Nagra T with Bottlehead external repro amp
Another not unknown guy in NY will get his NextGen equipped A80RC in a month or so...
I don´t easily recommend gear, but this is a no-brainer on par with the DaVa fieldcoil cart recommendation
best
Leif
I have recommended the boards to an old time friend of mine in Sweden who´s over the moon...he also already had the MTSL cards and also a Nagra T with Bottlehead external repro amp
Another not unknown guy in NY will get his NextGen equipped A80RC in a month or so...
I don´t easily recommend gear, but this is a no-brainer on par with the DaVa fieldcoil cart recommendation
best
Leif
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Leif,
reading the NexGen thread it appears only relevant to the Studer A80R/C? is that correct? unlikely even for the A-820 at this time. and also unlikely for any Ampex?
that's just from my scanning of the thread.
yes at the moment, but I know that they´re working on a "set" for A810 and as you probably know, the audio cards for A810/812 and 820 are identical....so hang in there....
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