Outboard Electronics

[Ghostboy74]

Hello All,

  I am new to the forum but have been enjoying Prerecorded Reel-to Reel tapes on my unmodified Technics RS-1506 for over a year.  I recently purchased a Revox PR-99 Reproducer that does 4-track and 2-track playback @ 7.5 and 15 IPS.  I was interested in upgrading the replay electronics for the means of improved replay and improved fidelity for transcription and was looking at vintage outboard electronics from Magnecord and Ampex, particularly the Ampex ATR-100's, 601's, 350's, and 354's but am unsure if they would mate well with this machine.  I would assume that there would need to be extensive modification/reconditioning just to get the stock machine to play prerecorded and Tape Project Tapes properly but do these other outboard electronics pose a greater challenge to retrofit (I understand the necessity to not only have the electronics receive the proper  values but that it is of greater importance that the replay equalization be correct in order to ensure proper tape tonal balance)? Would there be any disadvantage to using vintage outboard electronics vs. more current equipment? Any suggestions or advice would be greatly appreciated.

Cheers,

Bruce

[ironbut]

Hi Bruce, welcome to the forum. The older Ampex/Magnecord electronics would take work to get them up to factory spec. You've listed some pretty old stuff and finding exactly how to get them running and finding the parts aren't always listed in the service manuals. Then it would depend on the exact combination of electronics to heads on how much more it would take to interface them with either of your machines. You really need to get hold of the spec sheets for the electronics to have an idea which ones won't work in any practical sense.  The above is in regards to the playback circuits. The record circuits of all but the ATR electronics would require just as much if not more modification. Of course, these things can be done and if you have the design chops, you could end up with a great sounding rig. The ATR electronics are a complete unknown to me but I've seen that auction on eBay for at least a couple of weeks and nobody's snatching it up so if that's why you're considering it, be sure and consult with someone like Mike Spitz (at ATR Services) to find out if it makes sense.
So, I guess that's what you're really asking here right? Does it make sense? Not to me. And I have an old all tube Ampex already. Maybe if I had a pair of 351 electronics I might consider it, or if I had some MR70 channels, for sure. But you're talking about some serious money just to get your hands on them and then the fun begins (restoration/interfacing)

[mep]

Steve-I am curious why you mentioned the Ampex 351 electronics and not the 350s.  I thought the 351s are less desirable because they are not point-to-point wired and they don't have the outboard dual mono power supplies like the 350s do.

I own a pair of Ampex 350s and I am using them with my Otari MX-55.  However, I do not have the Otari wired for a direct head out and even if I did, there would be a an impedance mismatch between the Otari head and the Ampex head input.  There simply would not be enough gain going from the Otari head into the Ampex 350.  For the here and now, I am taking the output from the Otari playback electronics and plugging it into the Ampex line input.  This arrangement works great and sounds great. 

If I just run the Otari MX-55 straight into my Counterpoint SA-5.1 (line and phono stage upgraded by Mike Elliott), there is plenty of gain, but it sounds so ho-hum you would never want to seriously listen to it.  Once you run the output into the Ampex 350s and then into the Counterpoint, now you have something very special.

And yes, if you buy a pair of Ampex 350s, regardless of what the seller tells you, be prepared to spend at least $300-$500 to bring them back to spec.

[steveidosound]

Steve-I am curious why you mentioned the Ampex 351 electronics and not the 350s.  I thought the 351s are less desirable because they are not point-to-point wired and they don't have the outboard dual mono power supplies like the 350s do.

I own a pair of Ampex 350s and I am using them with my Otari MX-55.  However, I do not have the Otari wired for a direct head out and even if I did, there would be a an impedance mismatch between the Otari head and the Ampex head input.  There simply would not be enough gain going from the Otari head into the Ampex 350.  For the here and now, I am taking the output from the Otari playback electronics and plugging it into the Ampex line input.  This arrangement works great and sounds great. 

If I just run the Otari MX-55 straight into my Counterpoint SA-5.1 (line and phono stage upgraded by Mike Elliott), there is plenty of gain, but it sounds so ho-hum you would never want to seriously listen to it.  Once you run the output into the Ampex 350s and then into the Counterpoint, now you have something very special.

And yes, if you buy a pair of Ampex 350s, regardless of what the seller tells you, be prepared to spend at least $300-$500 to bring them back to spec.

Philosophically this bothers me somehow.
I know there are differences in sound between various types of electronics. But  using a set of tube record/play electronics as a unity gain line stage for no reason other than the "effect" they give the sound after the normal built in solid state electronics just seems like a waste. In my mind I am thinking which one is the "right sound" - that is to say the correct one, as far as frequency response, lack of distortion and other objective measurements are concerned. Otherwise your Ampex electronics are just a fancy preprogrammed eq to your subjective tastes.
Sorry for the rant, I probably should not bring this kind of thing up on an audiophile forum. I just have a hard time with things being "better than the original".
No, wait, I don't really have a problem with that, because I do think that some processing of sound can lead to better subjective and objective results. I am not afraid to use tone controls or EQ when necessary. But the "holy grail" to me and probably lots of other people here, is the best original sound processed the least through the most transparent, perhaps even simple, electronics chain, that also provides measurably reasonably good results  (that is to say we are not putting in devices that add 3% of distortion at all times because it sounds better somehow) and pleases our ears.
The discrepancies between subjective and measured data, particularly that which "measures worse" but "sounds better" have always bothered me.
I always am trying to convince my ears if it measures better it MUST sound better. Otherwise I am processing or re-synthesizing the original sound in some way.
Hope this rant made some sense...

[ironbut]

Hi Mark, I probably should have said "if I owned a pair of 35x electronics I'd consider it". Actually, if I owned a pair of 351's I'd rebuild/sell and put a down payment on an ATR 102. I was hoping you'd chime in here since you have first hand experience with matching electronics that were made for older heads to more modern heads. You can get higher output heads fitted to the RS15xx machines and I'd assume you'd be able to get them into an Otari too. I know that JFR fitted some Tascam/Panasonic heads that are more tube friendlyinto one of our members Technics headblock in the early days of this forum. I never heard them so I don't know how they stack up against the stock heads. But, here again, we have to ask ourselves if it's worth it?
Something to keep in mind here on this forum, there are several of us (I'm pretty sure I can count mep among us) who love to fool with this old/new stuff. Personally, I don't worry about how long these things take and I don't collect receipts. I'm just interested in getting the best sound I can within the limitations of the gear. But, if I had a project like you have staring me in the face, my attitude would be totally different.
That said, I think another avenue that you should seriously consider is modifying the existing electronics in your PR-99 ( I meant to mention this in my first post but go hypnotized by my own ramblings, sorry). Here's a link to Arian Janzen's wonderfully written tome on upgrading the PR99/B77 (you can download the pdf)
http://www.laocaudiosociety.com/tech.html

[mep]

Steve-Glad I got you on a rant and I hope you feel better now.  If everyone believed the mantra that "if it measures better it must sound better," then we would all still be listening to 1980s Japanese solid state electronics.  Those were the years of the Japanese spec wars with manufacturers all trying to outdo each other by seeing how many zeros they could have to the right of the decimal point in their distortion measurements.  We all know how good that crap sounded.

Further,  if everyone believed that "if it measures better it must sound better,"  we would have all junked our turntables, LPs, tape decks, and tapes in favor of the vastly better measurements of CD players.  After all, a $20 CD player will measure better than the most expensive turntable or analog tape deck right?

And so, those who make their purchasing decisions based on how something measures instead of how it sounds are probably doomed to owning mediocre  systems that measure far better than they sound to any set of ears that have sat in the presence of musicans playing music.  And based on your tag line "you really don't want to know what I'm listening to," maybe you are listening through 1980s Japanese electronics that measure fantastic.  And that is fine as long as you like the sound.

[bobschneider]

And based on your tag line "you really don't want to know what I'm listening to," maybe you are listening through 1980s Japanese electronics that measure fantastic.  And that is fine as long as you like the sound.

Hey, I'm listening to 1980s Japanese electronics right now - a Nakamichi CA-7A pre and PA-5 power amp, with Van Morrison on the LP-12 with a Benz Micro Ace SL cartridge, and North Creek Borealis speakers.  Sounds wonderful.  But then, the electronics were Nelson Pass designs licensed from Threshold.

[steveidosound]

Good. I hope I didn't cause any offense.
I am not one to actually make the argument that things that measure .00002% distortion sound better than things that measure .2  In fact I have heard filamentary SET amps through horns sound wonderful. They are certainly closer to the .2 than the .00002 distortion range at levels within their abilities. But I can't afford such equipment anyway. I don't begrudge all of you the right to enjoy your systems. I would choose something like this if I had the money also. I can hear the difference. It just bugs me that things with inferior specs. "sound better". I can also hear that  to me, almost any recording does not sound remotely like a live performance, but the difference between a $20 cd player and a 80s  mass market stereo receiver  vs. the best tape or vinyl rig through the best sounding cables and tube amp that you can get today,  either system driving the same set of whetever would be the best speakers with the high priced system, again compared to actual live performance, would go from a D+ with the poor system to perhaps a B- on the great one for thousands of dollars more. Accurate mechanical transducers such as phono cartridges and especially speakers are perhaps the biggest deal in the system for me.
But I own crap speakers ! ;-)  and  yes, their sound bothers me, though I have experimented and improved them slightly. Oh well, none of this should be a life or death issue.

All that having been said, my issue was more along the lines of  - are we deceiving ourselves into liking things better that color the sound, or are we just not properly measuring the areas where these other "lower specification" devices  audibly outshine  their  "better spec." counterparts.
Nobody was measuring transient intermodulation distortion for instance, or for that matter many other dynamic - non steady state - phenomena with complex waveforms back when they were quoting those low distortion figures for amps made so by lots and lots of negative feedback. Now we know what that does to the sonic signature of a device.

What I think is true for me, is that I love some technologies, particularly analog ones like vinyl and tape and so I want them to be better, and have found examples to prove my point. In other words, I am biased. My greatest fear is that in a controlled double blind test I would pick high bit rate digital over my beloved analog sources or almost worse yet, would be unable to distinguish them from some CD or mp3.
But rest assured I still think analog tape and disc as well as tube amps etc. are cool and sound great. It almost annoys me to hear a good digital solid state system because it is not the side I am rooting for.

BTW,  I did admit to some of the equipment I own here
http://www.tapeproject.com/smf/index.php/topic,622.0.html
at one point. Yes, there are some 80s (or 70s) Japanese electronics in there.
It is mostly just plain strange though!

[Ben]

I consider the $9.95 computer monitor speakers crap... even the $49.95 ones too.
I suspect one of the reasons music is so bad today, is that few people have heard
a good system with good music -- rap is not good music for testing fine detail in sound
system. the poor quailty of speakers seems to me in hindsight to be the reason.
I do know once I got away from cheap ($30) Bass Reflex speakers and went to better design ($1500) I got to hear real music, using the same full range drivers - ($300 pr)

[U47]

Hi Steve
This is one hairy pile of gear you've collected. You'll notice I don't divulge what scrap I'm listening to.... :-)

Rich Brown
Acoustic Arts
Portland, Oregon

[rbwtapeinterlink-Bob]

Hello All,

This is really great stuff. I've learned a lot and even got a laugh at how graciouse and respectful everyone is. This is how a forum should work. I mean with lots of respect for everyone's opinion. Thanks guys.

Bob W.

[PJ]

...My greatest fear is that in a controlled double blind test I would pick high bit rate digital over my beloved analog sources...

A couple years ago I was present at the Mission Street studio, listening to a really high-end, high bit rate, high resolution A/D and D/A. This was seriously good stuff, not yet commercially available at the time. Paul S. brought in a 1" two-track, 30IPS I think, recording which was routed to the digital stuff or bypassed with the flick of a switch. Trust me, you do NOT need to have this fear. Really good digital may be miles better than CDs (yes indeed it is!), but it still ain't analog and it's not difficult to tell, if the source and system are good enough.

People often claim added distortion of the pleasant sort will explain the preference for tubes, but in this experiment it was clear that added digital distortion damaged the sound. And I'm pretty confident that the measured distortion of the digital system was orders of magnitude less than the usual SET amp. And, for what it's worth, this was not a tube system either - ATR-100 to Michael's console, amps, and speakers.

[Ghostboy74]

I also would not fear  picking Digital over Analog.  Analog has a hard road to hoe because it all comes with a catch: WHEN PROPERLY SET-UP, an analog system will surpass most digital systems, but that is a pretty tall order for any machine (and the tech who is burdened by said machine); when properly done, it can be the best of the best.

Back in either 2002 or 2003 (cannot remember), I was fortunate enough to attend the AES in Los Angeles, and while there, I sat in on an audio demonstration where a group of companies (Muse, Avalon, and someone else) were comparing various bit rates and sampling frequencies vs. a 1" 2-track 30 IPS master tape(I think with Dolby SP). They were using a Studer A80 for playback of the tapes live, and had already digitized the tape at various bit depths and resolutions, playing these back from a hard drive and I think DCS converters. They started at 16/44.1 and went all the way up to 24/192 and DSD; granted, both DSD and 24/192 were not fully flushed out at the time and many improvements have been made since then, but the tape destroyed and stomped every digital playback scheme they used.  It was my first experience with 30 IPS and one I will never forget. 

Although I enjoy classical music and have worked as a stage manager in the past at my College's School of Music (CU-Boulder), only live events were tolerable  for me because I always felt like the perspective was off when I listened to CD or even LP, that a distance was created that placed the performers on a very narrow, almost two-dimensional plane, where the pace, timing, and size of the venue space were all distorted or lacking (not as much with the LP but surface noise, ambient temperature, environmental noise, etc. just masked too much detail).  I forget the piece they were playing now, but it was the first time I felt like I was truly caught up in the music and could almost feel every move of the performers; also, it finally sounded like it was recorded in a real space, rather than an artificial one.  Once they flicked the switch to play the digital files from their hard drive, everything fell apart and the music became less involving.  At the end, I begged them to play the entire piece they were demonstrating from the reel without engaging the digital so I could simply enjoy the piece; they tried to switch between the digital and reel again, but once I heard the 'truth', there was no telling my ear otherwise.

  It was too bad they did not have a 15 IPS copy of the tape, and even a 7 1/2 IPS copy to compare these against the 30 IPS master, but they figured that everyone there was more likely to be using 30 IPS than any other speed, and for them, they just wanted to see how much fidelity was lost when transferring the tape to digital.  The 24/192 files and DSD were close to the master (the DSD just a little closer but a little soft on top), and certainly might have won the day in comparison to 15 or 7 1/2 IPS, but I will ever know.

Cheers,

Bruce

[ironbut]

Great story Bruce. It's always great to know a little background of the folks around here. I hear the same thing with DSD ( the soft upper freq.s ) and I always wondered why that is. The only digital disc player I keep around is and SACD/CD player but that's for visitors for the most part (about the only thing I use it for is playing test discs and checking live recordings I burn for friends). If you get a chance to listen to one of the Tape Projects tapes, I think you'll be instantly transported back to that 30ips experience you related to. I've heard what the 1" masters sound like and I doubt that the 1/4" 15ips tape will be the limiting factor in any audible difference you could detect even in an A/B comparison.
As far as setting up a machine to play these tapes and get this kind of performance, I think that the guys have done a hell of a job of making this as painless and stable. That's one of the attractions of these pro-sumer machine IMHO. They may not get the final word in sound quality but for the price of admission, ease of use and low maintenance, they're unbeatable. Since your PR99 is actually all set up for playing these tapes, you may want to try one and see if it would be worth the money to have that machine upgraded (the upgrades in Arian's article would be a cinch for most techs or if you have some skills, you could do it yourself). If you like classical, the Arnold tape really displays what these tapes can sound like (although for pure musical value plus great sonics, the Suite Espanola) would be my pick.

Hey PJ,.. I was just wondering if Michael had those big Meyer Sound X10's when you listened? Those were very impressive when I heard them. Best solid state amp/speaker integration I've ever heard by a long shot! I was raving about those to Bob Hodas up at VSAC until he clued me in that they were his!

[Ghostboy74]

Thanks Steve. 

  I wanted to thank you in particular for the link; I remember coming across this months ago before I bought the PR-99, but had totally forgotten about it: very helpful and exactly what I was looking for.  Still looking for either a PR-99 or Studer A810 for remote recording/project studio work but has been put on hold because  I wish to get both my decks up to spec. and ready to sign up for the club. Once I have scrapped enough up by eating beans three meals a day for the next year, of course; I think my stomach (and Dr.) will understand. 

Cheers,

Bruce