Live recording on a RS-1500

[Dave Cawley]

This might be off topic or even off limits, if so please tell me ?

I want to do some live recordings on one of my RS-1500's.  Before that I will refurbish one and make sure it meets the requirements of the service manuals and all signal path electrolytics are changed.  I used to lap heads as part of my job years ago, I think I still have the touch.  I would dearly like the tape path mods and new brakes, hopefully my wish will be granted?

But the question is.  The bias and equalisation switches, what sort of tapes were they originally designed for?   May not be relevant but I won't sleep unless I know.

Thanks

Dave

[ironbut]

Hi Dave,

The bias and eq setting that come from the factory are as follows;

Ampex                         Bias     Eq
Grand Master                  2       2
372,373                         2        2

BASF
LPR35LH,SPR50LH           2       2
DPR 26LH
LP35LHS,DP26LHS           2       3

Scotch/3M                    Bias     Eq
211,212,213                   1        3
218,206,207                   2        2
Classic                            2        3
1500,2000                      2        3
250                                3        2

Maxell UD                       3        2

TDK Audua                      3       3

This is out of the owners manual.
Hope that helps you sleep.

[Dave Cawley]

Amazing, thank you!  http://www.aes.org/aeshc/docs/3mtape/aorprod2.html seems to identify them, but I'm struggling to see what the differences are?

Ah, see you edited it, give me a few hours.  This is just what I wanted.

Thanks

Dave

[docb]

Hi Dave,

We don't sell the parts for the tape path mod as a kit. The manufacturers often changed the size and material of some of the parts our new parts have to mate with. We have found that there is enough variation in the machines, both Technics and Otari, that we have to have several different types spacers, screws, and other parts on hand to adapt the mod to various production runs of these machines.

[ironbut]

Hey Dave,
Regarding recapping the record board, there's a list of the coupling caps (all 10uF) that was kindly posted by Charles King here somewhere but a quick search didn't turn anything up. I'm planning on doing the same one of these days. Charles also suggested that while you're in there (or have that board out) that unless you have a need for it, bypassing the mixer would be a good idea. Of course you won't want to do this if you plan on using the onboard mic preamps and the line inputs.

[Dave Cawley]

We don't sell the parts for the tape path mod as a kit.

Hi Dan.  I'm in the UK and mechanically skilled?  What can you do to help me and others in Europe?

Thanks

Dave

[Dave Cawley]

Hi Steve

My test area is here www.soundhifi.com/test.html It might take me a week, but I'll go through the RS-1500 chain and measure as I go.  I did the same thing on a Quad 34recently.  The before and after was really quite different.

Thanks

Dave

[Dave Cawley]

Hi Dan

I'm an expert on the Technics SP-10 turntable and have repaired several from the USA in the last two months.  A turntable less platter is quite manageable by Fed Ex, but a RS-1500 isn't.  I'm happy to share my knowledge on the phone to anyone here.  Dan, would you accept a telephone call from me in the UK to give me the benefit of your experience on the RS-1500 please?

Thanks

Dave

[docb]

Hi Dave,

If you have questions about standard service procedures found in the Technics service manual like tension, brake adjustment, alignment, speed adjustment, etc. Shawn and I would be happy to discuss them here. The details of the mods we do to the tape path are something we have decided to keep proprietary. It's not rocket science, but we do have an investment of time and money in refining the process.

[ironbut]

I think that when it comes to "live recording" Doc will agree that choice of microphones and their set-up is far more significant to your finished product than any mechanical tweaks that can be done to a properly operating machine. I think you'll find that someone who really knows what their doing in mic placement (and that ain't me!) will aways get the best results and may be the only ones who should have to worry about subtle tweaks on their machine.
That's surely not to say that these tweaks aren't worth it on the playback side of the equation. I think that most of us here on this forum are highly skilled listeners and things like the tape path mods can be quite striking, but recording is a whole different thing IMHO. Until your recordings can stand up to scrutiny, increasing the magnification will only help to reveal flaws.

[Dave Cawley]

OK, disappointed but all understood.  So, I'm checking and changing old capacitors right now.  Then I will pursue the bearings & tape path with a model maker friend before I take it into another friends professional studio.

Dave