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Author Topic: Tape project Machines page updated  (Read 7979 times)

Offline docb

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Tape project Machines page updated
« on: March 25, 2009, 10:04:20 AM »
My second least favorite thing after writing kit manuals is writing web pages. However the necessity arose and I ran out of excuses, so here is the newly updated page of tape machine info.

http://www.tapeproject.com/machines/machines.htm

At this time we are offering modification services to the Otari MX-5050 tape path. We do not have a DIY kit for this. I'm not sure if we can give the tutelage necessary for making the adjustments to the way the machine pulls tape after the mod. If we come up with a straightforward way to explain this we will consider a kit of parts.

Also, we are recommending the Ampex ATR 100 with our Tube Repro as the best possible setup for playing tapes. Studer guys, please don't hammer me for this. Studers are great machines, but I have only seen one Studer set up with our electronics that worked right. I think there should be more, but so far we haven't seen anyone but us take the time to complete a working combo. If a Studer guru approaches me with the same willingness to work together that Mike Spitz of ATR Services has, I will be willing to work with them to put together a setup for someone.
« Last Edit: March 25, 2009, 08:02:25 PM by docb »
Dan "Doc B." Schmalle
President for Life, Bottlehead Corp.
Managing Director - retired, The Tape Project

Offline ironbut

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Re: Tape project Machines page updated
« Reply #1 on: March 25, 2009, 11:13:32 AM »
Nice work Doc! You may hate writing this stuff but it sure doesn't show. I still go back and read sections of my Seduction manual when I'm unsure about a circuit that I know it includes.
 How do you like the Athon rollers over the stock Otari ones? Do you hear any difference with the urethane?
Anyway, it sure is a nice looking page now with lots of well explained choices. It kinda feels like the Tape Project's all grown up now.
I'd like to thank you guys, you really should be proud. Audio gear comes and goes but this is something else. These tapes and the ability to play them properly is something of lasting value.
steve koto
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Offline docb

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Re: Tape project Machines page updated
« Reply #2 on: March 25, 2009, 11:37:57 AM »
Thanks Steve,

I do like the Athan roller on an Otari, but I didn't like Athans as much as the stock rollers when we tried them on a Technics. I think the urethane Athan roller is pretty close in durometer to the Otari roller, but the Technics rollers are harder, and I'm guessing that helps keep the tape a little more stable over the capstan in the isoloop. The Athan rollers on the Technics seemed to blunt the transients a bit. Luckily the stock Technics rollers seem to hold up very well. A good scrubbing with Formula 409 usually freshens them right up.
Dan "Doc B." Schmalle
President for Life, Bottlehead Corp.
Managing Director - retired, The Tape Project

Offline jcmusic

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Re: Tape project Machines page updated
« Reply #3 on: March 25, 2009, 04:04:23 PM »
Hi Doc,
That is truly a really nice piece of work for a guy who claims not like to do it!!! Excellent explanation of everything the Tape Project involves in so far as the machines go, great job. I am however a bit disappointed about the non-diy kit, please tell me you have some sort of a plan for us who would like to do the mods ourselves!!!

Jay
Redpoint Model D TT/Soundsmith Sotto Voce Cartridge Otari MX 5050 BII/BH Tube Repro deHavilland Model 222
 Ah Njoe Tjoeb 4000, Rogue Magnum 99, Korneff 45 SET Amp, Klipsch K-Horns Bass Bins/2" Tractrix Horns 2" BMS Drivers, Vintage Tubes.

Offline rbwtapeinterlink-Bob

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Re: Tape project Machines page updated
« Reply #4 on: March 25, 2009, 06:45:06 PM »
 Doc,

I certainly wish I had you do my website. My attempt to get a nice informative website up and running is feeble compared to your effort. The next time I need website development work I will know exactly who to call on. Great job sir.

Bob W.
Bob W. (African American) VPI, Ref Standard Grado, Denon 103r, Threshold, DecWare tube pre and Classe pre amp, Jolida tube phono pre amp, (Peter Gunn) modified Magnapan 1.6, Tascam 32-2B & 42B tape decks, Parasound belt drive CD transport, Pacific Valve tube DAC, VPI  TT, various upscale cables.

Offline mikel

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Re: Tape project Machines page updated
« Reply #5 on: March 25, 2009, 08:25:49 PM »
Also, we are recommending the Ampex ATR 100 with our Tube Repro as the best possible setup for playing tapes. Studer guys, please don't hammer me for this. Studers are great machines, but I have only seen one Studer set up with our electronics that worked right. I think there should be more, but so far we haven't seen anyone but us take the time to complete a working combo. If a Studer guru approaches me with the same willingness to work together that Mike Spitz of ATR Services has, I will be willing to work with them to put together a setup for someone.

Doc,

awhile back i e-mailed you about somehow doing your tube repro on my 'Jeff Gillman' ATR-102; similarly to the ATR-102 in Portland with the Repro unit cut into the ATR rack. does your comment above only pertain to Mike Spitz's ATR's? or can you do the same mods yourself to mine (or other non-Spitz units)?

i am more motivated to do this on the ATR-102 than my Studer A-820 because on the Studer i get simple switchability between NAB and CCIR whereas with the ATR i need to jump thru a bunch of hoops; the Repro will allow for switchable EQ on the ATR. i can purchase some additional audio cards and just switch them for each EQ.....but then i have to buy cards, have them tested, and get someone to dial them in properly. i might as well spend the money on the Repro.

it seems to me that the Studer sounds pretty darn good 'stock'....and the ATR much less so. i have read about how some say the A-820 does not sound that good.....but either mine is different or my ears don't work too good. my mind and ears remain open to whatever.....

mikel
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Offline docb

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Re: Tape project Machines page updated
« Reply #6 on: March 26, 2009, 10:17:49 AM »
Hi Mike,

I can do the necessary cabling, but I don't have the facility to fabricate a rack mount in the rollaround like Mike did for Gary and Cindy's machine (and for the machine that Shunyata Research has ordered). I imagine one could find a local shop to do that fabrication if desired.
Dan "Doc B." Schmalle
President for Life, Bottlehead Corp.
Managing Director - retired, The Tape Project

Offline curry

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Re: Tape project Machines page updated
« Reply #7 on: April 29, 2009, 09:24:50 PM »
Hi gents,  being new to the forum, and r2r in general, I'm hoping one of you experts (hopefully Doc) can assist me. I now own a ReVox A77mkIV, 7.5/15 ips, NAB/IEC, 2 trk machine along with an EAR 834P tube phono-stage pre (which normally takes signals from a Sondek/Ittok/Sonata and feeds to an Audio Research LS3 line-stage). The question is; is it possible to use the EAR as a repro amp for the ReVox without excluding it's use as a phono-stage for the Linn? In other words, could I build a circuit that connects from the ReVox and plugs into the RCA's on the EAR, (or is there some other way) and what circuit would I need? Keep up the good works. Since I live in Jamaica, it's kinda difficult obtaining high-end hardware and soft-ware, hopefully I'll be able to afford a couple of those TapeProject tapes some day. 'Nirvana' - must be a nice place(sonically). Thanks for inspiring us wannabe audiophiles.                                                     Curry.   

Offline docb

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Re: Tape project Machines page updated
« Reply #8 on: April 29, 2009, 10:41:12 PM »
You should ask Tim de Paravicini this question - the 834P is his design.
Dan "Doc B." Schmalle
President for Life, Bottlehead Corp.
Managing Director - retired, The Tape Project

Offline curry

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Re: Tape project Machines page updated
« Reply #9 on: April 30, 2009, 02:28:16 PM »
Hi Doc, thanks for  responding. I agree, that might have been the prudent course if I were contemplating altering Mr. Paravicini's design, but I'm not. On the contrary, I'm hoping a circuit could be devised to operate from the tape machine and plugged into the RCA's on the EAR (or any other phono-stage, for that matter). However, if I've put you on the spot in some way, feel free to disregard this post. It certainly doesn't diminish my appreciation for the work you guys are doing. You've opened audiophiles' eyes to the possibility of taking our systems to a SIGNIFICANTLY higher level (closer to reality) with affordable vintage R2Rs, without having to contemplate $100k t/tables (which most of us can't afford,and which can't produce master-tape level performance anyways). And for that I salute you. THANKS AGAIN.                             Curry.         ([email protected])

Offline PJ

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Re: Tape project Machines page updated
« Reply #10 on: April 30, 2009, 02:57:49 PM »
I think this question has been addressed before on these pages, somewhere.

The basic problem is that RIAA equalization falls at 6dB per octave above 2100Hz, while tape equalizations are flat above the upper-midrange corner frequency. Unless you modify the equalization network inside the phono preamp, you will need additional gain to restore the high frequencies. In my experience, even if you have 20-30dB excess gain available, it would still be uncertain whether you could place the equalization in a way that did not make mincemeat of the signal-to-noise ration of the system.

It should not be difficult to change the equalization, and I would be surprised if deParavicini has not been asked this question before. However, based on our experience with the Bottlehead circuits, it would be much more difficult to make the equalization switchable - finding a place for the switch, and wiring it is such a way that the various stray capacitances and interference signals do not corrupt the sound, are significant difficulties that do not show up on the circuit diagram!
Paul Joppa
Bottlehead R&D

Offline ironbut

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Re: Tape project Machines page updated
« Reply #11 on: April 30, 2009, 03:12:12 PM »
Hi Curry, welcome to the forum.
There was another thread that was considering this path . The general conclusion was that I would be better not to try and reverse the eq of the RIAA and then apply the NAD/IEC eq to the signal. At the point at which these eq's are applied, the signal is pretty small and the less you do to it the better.
I think that using one of the Bottlehead solutions to eq and add the necessary gain to the head output is pretty hard to beat. There are currently 3 different paths you can take. The first is a modified Seduction which is very low in price. The next is a new phono stage kit that Doc is offering called the Eros (whose RIAA to NAB/IEC eq should be similar to the Seduction). It has higher gain than the Seduction which makes it a more universal fit to just about any system. I believe it's priced around $700. Both of these come as kits but Bottlehead does have finished Seductions from time to time and I'm sure the same will be true of the Eros (which hasn't shipped yet but that should happen any day now). The last and most expensive choice is the Bottlehead Repro Amp which is more flexible and is suitable for home and studio use. It's much closer to a statement product and is only available as a finished unit.
I built a Seduction a while back and it's a great beginners DIY audio project. I'm sure that the Eros will be more difficult but Doc's manuals are so explicit and detailed, it probably just requires more patience and time (being methodical is key with these things I think). IMHO the Eros will be the sweet spot when it comes to tape playback electronics for a long time. If you're an experienced DIYer, and after you've lived with the stock Eros for a while, you can experiment with mods and upgrades which I'm sure will elevate the performance a great deal and tailor the sound to your preferences and system.
steve koto
 Sony scd 777es(R. Kern mods)> Vpi Aires>Dynavector XX-2mkll>Bent mu>CAT ultimate>CJ premeir 140>Magnepan 1.6qr(Jensen xover)Headphone Eddie Current Zana Deux>AT ad2000,HD800 ,Metric Halo ULN-2 (battery powered),
 HE Audio Jades

Offline bobschneider

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Re: Tape project Machines page updated
« Reply #12 on: April 30, 2009, 04:08:15 PM »
It should not be difficult to change the equalization, and I would be surprised if deParavicini has not been asked this question before. However, based on our experience with the Bottlehead circuits, it would be much more difficult to make the equalization switchable - finding a place for the switch, and wiring it is such a way that the various stray capacitances and interference signals do not corrupt the sound, are significant difficulties that do not show up on the circuit diagram!

Is that an insurmountable problem?  A lot of older tube preamps have switchable phono EQ, including tape head EQ curves.  How did those preamps address that problem?

The reason I ask is that I'm rebuilding a Citation 1 with this feature (including NAB tape EQ and a tape head input), and want to try to include an IEC EQ so I can use it with Tape Project tapes. 
Bob Schneider

Offline curry

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Re: Tape project Machines page updated
« Reply #13 on: April 30, 2009, 04:16:06 PM »
Thanks guys, your explanations are enlightening, and thanks for the red-carpet Ironbut. A call to a local techie friend seems likely to be producing a solution for now. So I suppose I'll try that option 'til I'm able to go for the Eros (US$700 is a significant sum in terms of Jamaica's feather-weight dollar) I'm giving it serious thought though.

Offline docb

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optimization and compromise
« Reply #14 on: April 30, 2009, 04:40:01 PM »
I realize that my publishing of the Seduction tape head preamp conversion has potentially mislead folks to think that this kind of conversion of a phono preamp to tape head preamp is something that is perhaps switchable and possibly even something that could be external to the preamp itself. PJ has done a great job of explaining the reason that it isn't really the case. The Seduction is a fairly simple circuit with its passive eq and cap coupling between stages. Hence it is pretty easy to rip out the RIAA eq parts and install NAB and IEC eq in its place. But having all that stuff in there at once, or hammering the output of the phono pre into a tape eq shape post-preamp is creating too many compromises IMO.

Steve mentions the Eros. Point of fact the Eros is two different kits - Eros phono and Eros Repro. Not only are the eq components different between the two, the gain structure is different and to do this the operating point of the EF 86s is different for the two amps, requiring the construction different constant current source PC boards and different plate loads.

Yes there are old preamps that have settings for both. I would suggest that they are to some extent a compromise. Back in the days of those preamps tape heads usually had a pretty high inductance and impedance and high output level (and not always the best HF response - old Ampex heads as an example). Newer heads with lower inductance and impedance (and often better frequency response) may not find the older preamps as friendly.
Dan "Doc B." Schmalle
President for Life, Bottlehead Corp.
Managing Director - retired, The Tape Project