Machines

Machines

 

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Impression

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I picked up my fully tricked out Bottlehead 1500 this evening at the Mission Street Studio. Dan used it for the demos we heard tonight. I couldn’t wait to plug it into my system.

It was late, but I played the first tape of the Arnold Overtures album. I was totally blown away. I have both the vinyl and the CD – the vinyl has been on the Harry Pearson TAS Super Disc list and deservedly so. My vinyl front end is very good (VPI TNT HR, Lyra Helicon SL, Herron Phono Preamp) but the combination of the modified RS1500 with the Bottlehead electronics and this incredible tape, makes the vinyl pale in comparison. Dynamics, depth of sound field, sense of being transported to the event itself – total involvement in the music. I have to go to sleep now, but I can’t wait until tomorrow!  Dan said I got the first completely tricked out 1500 – after people hear this, there will be a long line.

-Charter Subscriber Larry Toy

 

 

Playback machine choices

We recognized early in the development of the Tape Project concept that there would need to be a reliable source of playback machines capable of delivering the full sonic quality of the Tape Project tapes.

With this in mind we developed several different paths for subscribers to follow to get to a machine that is capable of delivering all the sonic goodness of a master tape dub. The choices break down into two major groups – studio machines and what we like to call prosumer machines.

 

Studio quality machines

The studio mastering machines are the ultimate way to go if you have a very high end stereo system, the space to house a large machine, the budget to bring one up to top condition, and the willingness to learn how to maintain one. Studio mastering machines would include the Ampex ATR 100 series, 300/350 series, AG440 series; the Studer A820, A80, A807 and A810; and more obscure machines like the Nagra T-Audio, the Lyrec, the large Otaris like the MTR-10 thru 15, Scully 280, 3M M56 and M79, and various Sony and MCI machines. While these can all be very good machines, we recommend the Ampex ATR 100 and the Studers as the best choices because they sound the best and there are still parts and service available. Maintaining the other machines can become a frustrating experience because of a lack of parts and technicians capable of working on them.

The ATR Services ATR-100

If you want the best sound possible and have the space for a studio machine—and the budget—we can help you. We use Ampex ATR-100s to make the Tape Project tapes, so it stands to reason that the best possible way to play them back is with an Ampex ATR-100, built from the ground up by ATR Service Corp. to be better than when it rolled off the showroom floor. You have some choices of repro electronics:

  1. Stock playback electronics, which are OK, but we don’t recommend them for the best possible performance
  2. We can fit it with our Tube Repro amp by Bottlehead, the same repro amp used at the Tape Project demo room and at CES
  3. If you would like solid state repro electronics we can recommend the Aria electronics from ATR Service Corp.

Either of these latter options will give you a spectacular sounding machine.

The ATR Services ATR-100

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A stunning ATR-102 by ATR Services with Tube Repro electronics by Bottlehead

 

 

Prosumer machines

For some users there are disadvantages to the size of the typical studio tape machine and the expense of acquiring and maintaining it. So we decided to look at the many “prosumer” level reel to reel machines that were offered in the late 70’s through the early 90’s as alternative machines that would be easier to operate and maintain and take up less space in the listening room. Some models were regarded highly enough for their mechanical quality and reliability to be used in large numbers in radio stations, recording studios and other commercial applications. The Technics RS1500 series, Otari MX-5050 series, Revox A77/B77/PR99 models, and models by Tascam/TEAC were all considered as potential subjects for a program of modification that brings them to as high a level of sonic quality as possible.

Our choices for prosumer machines

For several reasons we ended up choosing the Technics RS-1500 and the Otari MX-5050 series as the two machines we currently offer modification kits for. They are well designed, they offer the versatility of both 1/4 track and 1/2 track playback heads and three tape speeds, and they are both gentle tape handlers. And we have developed a series of modifications to each machine that will move its performance closer to the studio quality machines.

NOTE

We used to perform these modifications in our lab. Unfortunately we found that the machines being sent to us were too often in need of major repair work far beyond what would be involved in our modification procedure, and too often they arrived poorly packed and subsequently damaged. On top of all of this shipping rates – particularly to locations outside the US – have become prohibitive over the past few years. Thus we decided to discontinue our in house modifications and offer the modification parts that we used in kit form, for you to install yourself or have a local technician install for you.

 

 

Otari MX-5050 series mechanical mod kit

The Otari MX-5050 has been a reliable workhorse in broadcast and budget studios for many years. While new Otari MX-5050 BIIIs are still available, they are so plentiful in the used market that a nice used one can be had for a fraction of the new price. We recommend the B2 and BIII versions. They come with everything needed to play Tape Project tapes – 15 ips tape speed, the ability to handle 10″ reels, a 2 track playback head (as well as a 1/4 track playback head for your favorite vintage prerecorded tapes), and switchable NAB and IEC playback equalization. All in all these are a good starting point upon which to build an excellent performing machine.

The best approach to modding the Otaris is to upgrade the tape path mechanicals and to modify the machine to use better external playback electronics. The options for playback electronics are discussed farther down this page. You may order the tape path mod kit and outboard playback electronics from the Bottlehead web site.

otarimod1You can bring the Otari’s mechanical performance closer to that of studio machines with modifications to the tape path. The cost for this basic tape path upgrade and alignment kit is $225.

You replace the stock plastic fixed guides after the pinch roller with ABEC-7 ball bearings where feasible (not all machines can be modified this way)

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You replace the fixed guides on the tension arms with adjustable guides with ball bearings and ceramic edge guides.

Other mods from other sources

There are other things that can be done to improve your machine. We do not offer these parts or services, but we have posted links so you can contact the companies directly.
You can upgrade the tension arms from the stock, easily bent aluminum arms to more rugged stainless steel arms that you can order from Athan Corporation. The pinch roller can be upgraded to an Athan urethane roller, as can the impedance roller.

You can fairly easily modify your machine for a direct output from the heads to outboard playback electronics, or have a local tech do it for you. The output jacks of your machine may be rewired to allow the playback head to be connected directly to an outboard reproduction amplifier that has CCIR/IEC1 playback equalization necessary for play of the Tape Project tapes- our own Bottlehead Tube Repro amp, Eros Tape Head Preamp Kit or another amp of your choosing.

And you should take special care with the heads. The stock two track and quarter track playback heads can be relapped by JRF Magnetic Science, or the two track playback head may be replaced with a custom extended response head manufactured by Flux Magnetics for optimum performance with 15 ips tapes.

The end result is a machine that approaches the sonic quality of the large studio machines, with more dynamic punch, snappier transients and better resolution.

 

 

 

Technics RS1500 series mechanical mod kit

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The Technics RS1500/RS1506/RS1520 series is another great tape machine with a strong following. It uses a servo reel control system combined with dual pinch rollers on a single capstan to maintain constant tension on the tape. This “isoloop” system results in very stable, low flutter playback. Like the MX-5050 the RS1500/1506/1520 can play at 15 ips, handle 10″ reels and has both 2 track and 1/4 track playback heads. We note here that the RS1700 is a 1/4 track only machine that does not have the ability to switch to a 2 track head. For this reason we do not recommend the RS1700 as a machine to mod for Tape Project tapes. The one possible shortcoming of the RS 1500/RS1506 series is its lack of IEC playback equalization (except for the RS1520, which does have IEC playback eq). In actual practice this is not such a big issue, because the quality of the playback electronics in all of these late 20th century prosumer grade machines is dismal. The way to get the fullest benefit of the sonic quality of Tape Project Tapes is to use better outboard playback (repro) electronics anyway.

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You can bring the Technics’ mechanical performance closer to that of studio machines with modifications to the tape path. The cost for this Bottlehead basic tape path upgrade and alignment kit is $249.

The mechanical improvements take the sonics of the Technics a bit further with refinements in the materials and configuration of the fixed tape guides. The end result is a machine that handles tape extremely well and sounds cleaner, with better low level resolution and snap.

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Our ball bearing and ceramic edge guide upgrade, now incorporated as a standard part of the tape path upgrade (where they fit – not all machines will accept these)

Along with the tape path improvements you will install improved brake pads that better maintain the factory brake tension specification, update the tension arm roller bearings with higher quality ABEC 5 bearings and modify two of the fixed guides to ABEC 5 ball bearings with abrasion resistant edge guides. You will be shown how to carefully adjust the reel servo controlled tape tension to factory specification.

Other mods from other sources

There are other things that can be done to improve your machine. We do not offer these parts or services, but we have posted links so you can contact the companies directly.

Rebuilt pinch rollers are available from Athan Corporation if necessary, though the stock pinch rollers seem to hold up quite well.

You can easily can modify your machine for a direct output from the heads to outboard playback electronics, or a local tech can do it for you. The output jacks of your machine may be rewired to allow the playback head to be connected directly to an outboard reproduction amplifier that has CCIR/IEC1 playback equalization necessary for play of the Tape Project tapes- our own Bottlehead Tube Repro amp, Eros Tape Head Preamp kit, or another amp of your choosing. The options for playback electronics are discussed farther down this page. You may order the tape path mod kit and outboard playback electronics from the Bottlehead web site

You should take special care with the heads. The stock two track and quarter track playback heads can be relapped by JRF Magnetic Science.

extendedhead1500

Or the two track playback head may be replaced with a custom extended response head manufactured by Flux Magnetics for optimum performance with 15 ips tapes.

The end result is a machine that approaches the sonic quality of the large studio machines, with more dynamic punch, snappier transients and better resolution.

 

 

But I need to know which one is best!

Obviously we like both machines or we wouldn’t be recommending them. In stock form we like the Technics a wee bit better. Neither machine is as good mechanically as a serious studio machine like an ATR, Studer, or Nagra T. The Otari has better brakes, the Technics has exceptionally low wow and flutter. The Otari is more rugged, the Technics is better looking. The Otaris tend to go for lower prices on the used market, while the Technics tend to have a higher resale value.

In modified form both the Technics and Otari machines get a lot closer to the studio machines. We have found that the modded Otari is a bit more snappy and articulate, while the modified Technics leans more towards smooth and liquid. The differences are fairly small.

Of the Technics models only a stock RS1520 can play our IEC tapes (the RS1500 and RS1506 don’t have IEC eq), while the stock Otaris have IEC playback built in. However in our opinion both machines need to be modified to use outboard playback electronics to be able to deliver the full quality of the Tape Project albums. The stock circuits just don’t cut it (nor do they in the studio machines, for that matter). With upgraded electronics and modified tape paths either machine will deliver the goods.

Here’s what an owner of both an ATR Services ATR 102 with Bottlehead Tube Repro and a Bottlehead modified Technics RS1500 with Tube Repro has to say:

“The ATR with Tube Repro is fantastic, the level of realism, detail and easy goingness never ceases to amaze me. The big surprise was the Technics with the Tube Repro. I upgraded to the ATR at the same time as the Tube Repro so I hadn’t really compared both decks with the same electronics. This time we did it one after the other. The Technics with Bottlehead mods and extended response head is very close to the ATR! The guys at Bottlehead have done a great job with the mods. Don’t get me wrong, there is some difference and it was clear that the big transport could do things the small one couldn’t. But considering the difference in cost and size, this is the poster child in diminishing returns.”

-Tape Project Charter member Xcortes

Playback heads and electronics

The tape head and its accompanying preamp, or repro amp as it is known in professional recording is 50% of the equation when it comes to reel to reel sound quality (the other 50% being transport mechanical quality). Right up front will say that in our opinion none of the stock tape machines that we would recommend for a home listening room – studio or prosumer – has the ability to deliver the full resolution of Tape Project tapes. But in modified form they can sing.

Luckily the playback heads of most studio machines are very good, as are the playback heads of most prosumer machines. This makes use of a stock playback head an economical solution for modified machines with budgetary limits. Slightly worn heads can be relapped at a reasonable price and stock replacements are available for a lot of machines.

Ext-Technics

For the best possible performance one can install an upgraded extended response head manufactured by Flux Magnetics, shown above. These heads will bring the frequency response of a prosumer machine up to the level of the best studio machines, resulting in an improved sense of extension at both ends of the frequency spectrum with more air to the highs and a flatter and more substantial bottom end.

Unfortunately the stock solid state repro electronics found in studio and prosumer machines suck. At Bottlehead we have been designing and selling exceptional tube preamps for 15 years. And so it was natural for us to develop tube electronics that could reveal the amazing quality of 15 ips analog tape when used in conjunction with both stock and custom playback heads.

We offer a few choices of tape head or repro amps. 

At the top is our Tube Repro. The Tube Repro is designed with a studio quality machine in mind, but it will also bring the sonic quality of a modified prosumer machine very close to that of a studio grade machine. It is the best match for a Flux Magnetics Extended Response head

Perhaps the best bang for the buck is our Eros kit preamp, which is available in a tape head version. It uses the front end circuitry of the top of the line Tube Repro with a simplified output and high value, non “boutique” components.

 

 

The Tube Repro

An excerpt from the review by Myles Astor of the Bottlehead Tube Repro tape head preamp in Positive Feedback Online, November/December 2009:

“The Repro, and one must allow at several hours of being powered on and/or playing music before critical listening, is extremely quiet and transparent, allowing one to resolve the minutest music details on The Tape Project tapes. (the tape deck too benefits from a couple of hours being on before playing.) Through the Repro/Technics combination, The Tape Project tapes display a soundstage limited only by the associated equipment and software. Instruments and singers have a much more realistic sense of body and realism. Strings are as sweet as sugar, if not gently rounded, without tipping over into euphonic territory. One can literally hear the violin bow changing direction and feel the pressure of the bow on the strings. Low frequencies are very dynamic…”

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We love the articulate, natural, enveloping sound of tube electronics.Bottlehead has been putting out highly regarded tube gear for 15 years. The Bottlehead Tube Repro amp is a statement piece that will run with the best of what is out there.

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The Tube Repro is designed as a versatile tape head preamp that works well with medium to high inductance playback heads. It has been developed from the start as the perfect match to Flux Magnetics Extended Response playback heads. It can output both single ended signals at the consumer level -10dB through RCA jacks and balanced signals at studio level +4dB through XLR jacks. CCIR/IEC1 and NAB/IEC2 playback equalization are each available with the flip of a switch, and other playback EQs are possible on a custom order basis. Most any modern tape recorder, once modified to direct output from the playback heads, will work with the Repro.

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The Repro’s circuit is designed to keep the signal as pure and uncolored as possible, while avoiding the harsh and sterile sound that can come from some gear that claims “great detail and speed”. EF86 pentodes are used at the input, chosen for their high gain, low noise and sweet sound. The signal passes thru a direct coupled passive equalization network to a 6DJ8 type dual triode. From there the signal can be taken at the single ended RCA outputs. To achieve a studio level balanced output the signal passes through a 6CM7 gain stage to balanced transformer XLR outputs.

The power supply utilizes a separate hybrid tube/solid state shunt regulator for each channel which tightly regulates the high voltage, giving a sense of bandwidth and separation unparalleled by other means of power supply regulation. Each signal tube is isolated from power supply noise by a Camille Cascode Constant Current Source, giving the sound a black background and bringing the dynamics to an elevated level of realism. Premium quality components are utilized throughout, Schottky diodes, premium Panasonic electrolytic capacitors, high quality Teflon and polypropylene coupling capacitors, and a range of premium resistors from tantalum to metal film to carbon composition, each one chosen for optimal performance in the job at hand. Individual PEC trim pots for level are accessible from the front panel, as is a selector for playback equalization. Tubes and output transformers are socket mounted on the back panel in the tradition of classic studio gear, to allow for quick and easy changes to suit the listener’s taste.

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Price is $4000. These preamps are hand built to order and require a 50% deposit.

 

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An example of a custom Tube Repro installation –

Here are some photos of Doc’s Nagra T Audio with the custom Tube Repro we built for it. This machine is used in Doc’s personal system and is our “show pony” that we take to various meets and shows.

The Repro is in a standard 2U high cabinet. This Nagra came in what seems to be a fairly typical configuration with a roughly 1U high time code generator module above the meter bridge and a roughly 1U blank panel below the bridge. The time code unit, the blanking panel and the rear cover panels were all removed and the meter bridge was relocated at the bottom of the doghouse. The labels are hard to read in the photo, but the big switch is the playback EQ selector with IEC, NAB and Nagramaster settings. The small flush mounted trimmers adjust left and right output level. Head damping is adjusted by means of internally mounted trimmers at the input.

 

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From the back – the head cables inside the machine were rerouted to the Tuchel connector with the braided cables coming out of it at the right end of the transport tub. Those cables connect to the Repro inputs at the left end of the Repro. The little red pigtail that is hanging above the Tuchel connector is connected to the internal repro electronics and by swapping the pigtail for the braided cables at the output jack one can reconfigure the machine to the stock playback electronics. The Repro transformer balanced outputs have split cables on them. The braided cables going out of the picture go to the line preamp and the red and black cables are routed to the line input of the meter bridge. By switching the meter to monitor record one can meter the Repro output. The Tube Repro can be ordered from the Bottlehead web site.

 

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Eros tape head preamp kit

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If you are on a tight budget or you don’t want to put up a lot of money at the start of getting into tape, you can build a Bottlehead Eros Tape Head Preamp kit with switchable NAB/IEC playback equalization. You can connect to your direct-tape-head-out modified RS1500 or MX-5050 (or any other deck modified to direct head output) with some 1/2 meter interconnects in your favorite flavor. The stock heads on either machine work well with the 50dB gain of the Eros tape head preamp, and the Eros is happiest running into a line preamp with an input impedance of 50K ohms or higher and a gain of at least 10dB. Bottlehead has a reputation as the best place to go for a first time builder and the Eros phono version already has a reputation as a great small signal preamp. The price for the tape head preamp version of the Eros kit is $799. Don’t want to build it yourself? Ask a Bottlehead approved tech to build it for you.