AK (hot rodded) Ampex ATR-102's w/MR-70 Preamps replaces my Studers.

[andromedaaudio]

Remember those amps with .0001% THD?

I guess you mean Halcro , well at least i like them


Ps Jeff may be you can send mike a machine with your built in cards for a try out / comparison
May be mike is in for a comparison and willing to post the results
I reckon measurements are a tool to get good sound , it doesnt implicate that good measuring gear automatically sounds good

 

[christensenleif@msn.com]

I thought it was Technics in the 70s

 

[Foxbat]

I think asking the question about measurements is relevant - it applies to any brand equally.

Plugging your own product steps over the line, I agree.

 

[NextGen]

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.

You are absolutely right in questioning specs that bear little resemblance to what is heard or can be heard, or come at the expense of other critical characteristics not mentioned; too often specs have been used as a cheep way to hawk equipment to unsuspecting buyers, and today it is especially easy to report super low THD numbers using op amps with 160dB of open loop gain (but 10 Hz dominant pole) and consequent miserable sound, as just one obvious example.

This is probably not the place to have a detailed discussion on our particular design philosophy, but as a designer youself you must agree that the Art of Engineering is in the choice of compromises you make in tradeoff of superiority in other areas; there is no perfect design. We use measurements as a guide and confirmation, and yes inspiration, especially where these can be reliably tied to listening results by us and published by others (such as audibility thresholds on group delay distortion, slew-induced distortion, etc).

In general, I approach audio design from an information theoretic perspective: that the best design is the one that captures and preserves the most information, but in the end all human perception is to one extent or another subjective, audio systems, listeners, and listening circumstances are highly variable, and some listeners (it has been shown) actually prefer "lossy" systems or can tell no difference. Nonetheless, I accept the information theoretic approach as the best and "soundest" approach (no pun intended) to audiophile nirvana: I would rather convey more information than any listener can process than less.

With the measurements I depend on I would certainly be reluctant to argue that if it measures good and sounds bad in a particular system that it must be good, but I would question the limitations of the system or source material; but I would also be the last to argue if it measures bad and sounds good that that it must be good.

Regards,
jeff

 

[Mike Lavigne]

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....

ok, thanks. so we need to have one of these A-80 RC's with the Next Gen cards be compared to various Ampex ATR-102's with MR-70's. but, of course, Studer A-80's are all in different stages of wellness. whereas the 'AK' Ampex ATR-102's with the 'AK' MR-70's are what i am talking about.

might that compare ever happen? hope it does.

data be damned.

 

[Foxbat]

Mike, the simple truth is there is no one universal truth. When put in front of the same system, you are lucky if 60-70% of people will agree on the results.

That is why some people swear by Krell and others by Cary - sorry, don't mean to push either one, just citing two typical examples of more or less opposite approaches.

Don't underestimate the power of personal preferences.

 

[NextGen]

I wasn't trying to "plug" our NextGen A80R/C repro cards in this forum; I will gladly leave that to user comments from our customers.

My interest is strictly as audiophile and engineer (I have 10 US Patents in Wireless and Ultra-Wideband Data Acquisition), and advancing the State of the Art in analog tape electronics:

I like to see the measurement data behind various audiophile sonic performance claims - and this applies equally whether the measurement data does or does not appear to support certain sonic claims - for every audiophile's benefit; how else can we learn from, validate, and assess what the measurements can tell us - and what they cannot tell us - about actual sonic performance: which measurements and measurement results are really important to excellent sonic performance, which less so, and which measurements/measurement results appear either weakly related, or unrelated to performance (i.e. neither causitive or correlation).

And finally, it might provide some insight on what other equipment- or human auditory- measurements might further illuminate what is being heard.

Mike: from what I understand, you have a highly-regarded reputation as an audiophile with much experience, excellent equipment, and listening room setup - so I expect your comments regarding sound need be taken seriously. All the more reason to have the measurements along with the comments.


If the AK hot-rodded ATR-102/MR70 is as good as you suggest sonically, a comparison set of measurements to those we have published (record/repro Impulse response, group delay characteristics with frequency, magnitude frequency response, THD versus fluxivity, and coherence function at a minimum) should be informative if not enlightening, and might well benefit audiophiles today and in the future with further improvements in top-end electronics and possibly transducers including loudspeakers.

Our NextGen outboard standalone tape (Record, Repro, and Bias/Erase Oscillator) electronics will be ready soon, so perhaps we will have the opportunity by this summer to try some side-by-side comparisons, either with the Ampex or another transport. I look forward to the opportunity.

Jeff

 

[NextGen]

Mike:

Just to let you know, going from the Ampex ATR-102 432 Khz Bias down to 150Khz bias will increase tape Bias noise by at least 2-3 dB (due to Bias lower sidelobe and anhysteretic magnetic tape oxide behavior) which means at least 2-3 dB reduction in A-wtd SNR. This applies to recording. I expect as well the MR70 Oscillator will have high even harmonic content, phase noise, and frequency drift compared with the crystal-derived ATR-102 electronics, which will also raise even order distortion in record, and small amplitude fluctuations. So the hot-rodded MR70 may not be the best choice for recording.

Actually, NextGen are going in the other direction: raising the A80R/C Bias frequency from 150Khz on the A80R/C to 250Khz with our new oscillator, crystal synthesized, improving A-wtd SNR by 2 dB, as well as big reduction in even order harmonics and great improvement in tape playback amplitude stability (reduced amplitude modulation sidelobes) at all speeds.

Cheers
Jeff

 

[Mike Lavigne]

I wasn't trying to "plug" our NextGen A80R/C repro cards in this forum;

reading it, that was how it seemed to me. but i do appreciate you saying that it wasn't. thanks.

I will gladly leave that to user comments from our customers.

i see this as (1) customer listening feedback (2) discussion (3) data and technical. manufacturers should be answering questions. not challenging other products credibility. state the facts. allow the discussions to flow.

but my views are just my own and how i see it. i would never ask my gear manufacturer to get aggressive about their perspectives. but certainly it happens all the time. it's a slippery slope. your products rely of the condition of the reel to reel deck for the result. so you don't control it. your numbers are theoretical based on the ideal deck. unless you redo all the 45-50 year old decks that use your product.

My interest is strictly as audiophile and engineer (I have 10 US Patents in Wireless and Ultra-Wideband Data Acquisition), and advancing the State of the Art in analog tape electronics:

this is good news for tape enthusiasts and i applaud it. we need more people such as yourself.

I like to see the measurement data behind various audiophile sonic performance claims - and this applies equally whether the measurement data does or does not appear to support certain sonic claims - for every audiophile's benefit; how else can we learn from, validate, and assess what the measurements can tell us - and what they cannot tell us - about actual sonic performance: which measurements and measurement results are really important to excellent sonic performance, which less so, and which measurements/measurement results appear either weakly related, or unrelated to performance (i.e. neither causitive or correlation).

And finally, it might provide some insight on what other equipment- or human auditory- measurements might further illuminate what is being heard.

honestly i don't care a whit about this stuff. not that relating measurements to sonic results has no merit. just not something i'm going to pay much attention to. i do read the technical numbers, and retain them as a data point to be part of the picture. but only as a data point and not as the truth for me. a piece of evidence to be considered.

but some here like to discuss how many angels you can get on the head of a pin. and maybe at some point these discussions might result in some betterment of the sound. but i will not participate. since my ignorance would be confirmed....not just assumed. with 'AK' he starts to relate the techie stuff then sees he has lost me.

Mike: from what I understand, you have a highly-regarded reputation as an audiophile with much experience, excellent equipment, and listening room setup - so I expect your comments regarding sound need be taken seriously.

thanks.

All the more reason to have the measurements along with the comments.

not anti measurement, not anti anything except being anti.

If the AK hot-rodded ATR-102/MR70 is as good as you suggest sonically, a comparison set of measurements to those we have published (record/repro Impulse response, group delay characteristics with frequency, magnitude frequency response, THD versus fluxivity, and coherence function at a minimum) should be informative if not enlightening, and might well benefit audiophiles today and in the future with further improvements in top-end electronics and possibly transducers including loudspeakers.

if 'AK' wants to do that it's up to him. but i'll not ask him about it.

Our NextGen outboard standalone tape (Record, Repro, and Bias/Erase Oscillator) electronics will be ready soon, so perhaps we will have the opportunity by this summer to try some side-by-side comparisons, either with the Ampex or another transport. I look forward to the opportunity.

Jeff

best wishes with that project. happy to compare a Next Gen A-80R/C to my 'AK' ATR's at some point.

cheers,

Mike

 

[Mike Lavigne]

Mike:

Just to let you know, going from the Ampex ATR-102 432 Khz Bias down to 150Khz bias will increase tape Bias noise by at least 2-3 dB (due to Bias lower sidelobe and anhysteretic magnetic tape oxide behavior) which means at least 2-3 dB reduction in A-wtd SNR. This applies to recording. I expect as well the MR70 Oscillator will have high even harmonic content, phase noise, and frequency drift compared with the crystal-derived ATR-102 electronics, which will also raise even order distortion in record, and small amplitude fluctuations. So the hot-rodded MR70 may not be the best choice for recording.

Actually, NextGen are going in the other direction: raising the A80R/C Bias frequency from 150Khz on the A80R/C to 250Khz with our new oscillator, crystal synthesized, improving A-wtd SNR by 2 dB, as well as big reduction in even order harmonics and great improvement in tape playback amplitude stability (reduced amplitude modulation sidelobes) at all speeds.

Cheers
Jeff

the 'AK' ATR-102/MR-70 is not set up for recording. i have a separate 'stock' 'AK' ATR-102 with 1/4" and 1/2" heads that does record.

 

[Ki Choi]

The 3xx and 4xx series Ampexes lack some modern day niceties, but they still handle the tape well... provided you adjust your ways slightly. For instance, never hit Stop from a rewind.

I also added an electronic tape counter to one of them, makes it much more convenient.

Hi Victor

Did you mean not to hit PLAY from a rewind?

Ki

 

[Foxbat]

Hi Ki,

No, I meant Stop, as at least on my 3xx and 4xx series machines pressing Play while spooling does not do anything - it is disabled. You always need to press Stop first.

Problem is those machines spool very fast, so the pros always shuttle the FF and Rew to slow the tape down before hitting Stop. I usually do that when going full speed. It it barely moves I allow myself some leeway and go directly to Stop.

 

[adrianywu]

you were part of the underground.

for sure there were serious tape heads prior to the Tape Project. but there was no information out there for audiophiles to find. you had to know the secret handshake. i know because i looked. looked hard. nothing. i had to scrape around to find my ATR-102 and my first Studer. 6 months to a year after i got my decks, info started to come out and the Tape Project started their on line forum. from there it opened up more each year.

I got my Nagra IV-S in 1999, and my T Audio a few years later. There was no commercially available tapes, and we had to make our own recordings with the local orchestra (Hong Kong Philharmonic under Edo de Waart) staring in 2005. People were throwing these machines into the trash in those days. My IV-S was sold by the BBC for 2000 quid (including QGB). Nagra sold me the T Audio, fully refurbished with new heads, for 6000 CHF. It was considered expensive in those days, since one could buy a Telefunken M20 for about 800 Euros. The tape project changed all that, and in any case, after Edo was replaced by Jaap Van Zweden, we lost the permission to record for the orchestra. Recordings made with the IV-S are really quite something, for such a simple machine.

 

[kodomo]

My biggest audio regret is letting this 102 go!

 

[Foxbat]

I feel your pain! I would be kicking myself too, it is my favorite machine.

 

[Mike Lavigne]

i have convinced my wife to allow me to buy the 1/4" MR-70 spec headblock and second set of MR-70 preamps for the 1/4" from 'AK', matching my other pair for the 1/2". so i will be able to play all my tapes (both 1/4" and 1/2") with either the stock 'AK' ATR-102 or the MR-70 'AK' ATR-102. and i found an appropriate rack for the -4- MR-70 preamps.

not sure how many of the 1/4" tapes in my collection i was intending to have to transfer to 1/2" so i could listen on the MR-70, but it might have been more than a couple. maybe a bunch. now i won't have to sweat which tape width it is. 80% of my collection is 1/4".

this was hard for me. painful. but down the road i would have regretted not biting the bullet and finishing the deal. it's a one time opportunity.

not sure when 'AK' will deliver them.

 

[dminches]

Mike, have you been able to compare the sound of the stock ATR to that with the MK-70 electronics?

 

[Mike Lavigne]

Mike, have you been able to compare the sound of the stock ATR to that with the MK-70 electronics?

yes and no. not played any recordings where i have both 1/4" and 1/2" sourced from the same tape. and i've not done any A/B where i was trying to assess the differences critically. just listened casually.

both are beyond my previous tape experiences. it's too simplistic to say one is solid state and one is tubes. while true, neither sound like solid state or tubes. in that way, either could be darTZeel, or beyond along those lines.

maybe the MR-70 has the finest degree of grainless, musical flow and ease i have yet heard from any music reproduction. and the stock deck has this ultra ultra insightfulness. they are different, but both are truth sayers that seem right.

but way too early to try and pigeon hole either. i'm just relating what enters my mind that maybe gives you an idea.

 

[Afveep]

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.

Dan is the best! Did my ATR rebuild originally at ATR Services and have now recently used him through his new company in Philly. Highly recommended.

 

[Bruce B]

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.

These cards are as good (Sounding/Measuring) as Jeff says they are.....

Congrats Mike... Andrew's work is top notch...