Posts: 161 Location: South London Joined: September 22, 2002
I've been thinking about doing some mods for ages, but haven't quite gotten round to it yet.
I've read of someone replacing the stock record level pot with a stepped attenuator, which was apparently a big improvement. Same went for replacing the standard head leads with something more heavily shielded.
I think other areas for improvement would be low-noise regulators for the head amps, bigger decoupling caps generally to keep ripple and noise low on the power supply rails, and higher quality input and output op amps (my old JVC had 4558s, which seem to be regarded as about the lowest of the low on the Tweaking Asylum).
Cheers, Jon.
Re: anyone had any mods done to their tapedeck??, posted on June 26, 2004 at 08:13:36
Jack Seaton
Yes. I didn't do any of the mods myself, Paul at Tube Research did them all along with his machinist. I'll tell you the mods to one of the Scullys:
They started with a Scully 270 which is a large chassis playback only machine which will play the large 14 inch reels. First, everything was removed from the deck plate and a special 3/8 inch thick aluminum panel was machined to replace the original. The Scully SP-14 has a 3/8 inch deck plate. Next Paul suggested new drive motors and capstan motor, which he'd found through a friend at Skywalker Sound. This guy also had the rare factory flywheels which mount on the bottom of the drive and capstan motors for added speed stability and the parts to convert my machine to playback my 30 IPS masters.
All internal signal path wire is FIM Cable, I have a dozen different head stack mounting blocks which can be changed within a few minutes because different heads sound better with different reels (head spacing, etc.). He pretty much rebuilt the entire mechanical and scrapped the original Scully circuit and built his for me.
My previous deck was an ATR Services ATR-102.
Re: anyone had any mods done to their tapedeck??, posted on June 26, 2004 at 11:50:08
Hello. Sounds like things I would be interested in exploring. Particularly with the output stage.I always have to run the volume up higher on the preamp to drive the amp at the same level as my other equiptment does at a lower volume setting. Basicly what I am looking to do is improve on the power supply and the input/output stage with more signal output or mabey able to make it adjustable.Improving on sound quality is always a bonus too. The head leads sound interesting also.
Regards, Tony
Re: anyone had any mods done to their tapedeck??, posted on June 28, 2004 at 09:38:07
rosebud
hi to all. i am looking for a revox b-77 mk-II high speed (7.5/15ips) in very good condition with upgraded electronics, or at least a repair shop in the continental u.s. that can do some nice mod's, since my stereo system is pretty nice. commercial decks use cheap parts, and the pro decks are usually the size of a desk. i have an otari mx-55, but even it has a manual i can just barely comprehend (doing fine calibrations, test tapes, etc.etc.) any replies would be appreciated. i once saw a studer a-80 with levinson electronics (on "cards") but the machine must have weighed 200 lbs...!
Mods to my Nak..., posted on July 7, 2004 at 17:50:20
Posts: 1124 Location: Ontario Joined: October 27, 1999
This was my first go at modifications..mind I got someone else to do it. Basically I replaced the RCA jacks (located on a flying circuit board made of stamped steel) with proper RCA wired with Kimber Kable. A quite large difference! I then damped the chassis & added an IEC, small difference if any. But the tapedeck did make less noise when running.
My Mods to Sony TCK-670 3 head cassette Deck, posted on July 23, 2004 at 17:08:07
I have a three head, three motor, closed loop dual capstan Sony deck (TCK-670) that I did the following mods on:
1. Replaced all electrolytic bypassing & coupling caps with Panasonic HF units (also with poly bypasses)
2. Improved all power supply capacitors with bigger & better units (with poly bypasses) and added super fast soft recovery diodes.
3. Built a custom output stage after Dolby chip using BB 2134 op-amp with low output impedance.
4. Improved input level volume control.
5. Added chassis damping and AC filtering.
After the mods, and using something like TDK SA-X cassette tape (and Last head treatment), the record/play sound quality is very nearly identical to CDs used to make the cassettes. HQ parts do quite a bit for even units that already sound very good, and I have to say I was surprised at just how good cassette playback could be for a non-Nak deck! Good enough for all but very critical listening.