TP-028, Nat Adderley's Work Song is now available

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Messages - scully280

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Anybody have a source for schematics for the Dolby Labs 330?

Prerecorded Tapes / Dolby level for Ampex Dolby tapes
« on: March 08, 2007, 10:22:21 PM »
Does anybody have any information on the level that Ampex assumed for the standard Dolby level on their later pre-recorded Dolby B tapes?  Since they didn't record any Dolby tones it's not clear.  I have always guessed that they used 185nW/m as the Dolby level, but I wonder if somebody has some real (reel?) information.

Prerecorded Tapes / Re: Level problems with pre-records??
« on: March 08, 2007, 10:16:59 PM »
For Stereotape and Barcaly-Crocker tapes there were always Dolby Tones with B-C giving us the luxury of tones on both sides.  This allowed the fussy user to match the level on the tape to the Dolby calibrated play level on the Dolby decoder.  My experience with bunches of these tapes is that the the Dolby levels seldom match from side to side and tape to tape and sometimes are off by a lot at least from side to side.  Not surprising that the levels vary from tape to tape as different batches of tape will have different repsones, but the channel to channel balance problems are annoying and harder to attribute; perhaps just the vagaries of high speed dubbing.  Makes me hope that the Tape Project tapes are subject to the same type of quality control for 1:1 dubs that the site in Ironbutt's post "Some R2R resources for first time owners" talks about for 70's broadcast automation dubs. 

Sounds like there are a few out there enjoying Dolby type B pre-recorded tapes whether they are Barclay-Crocker, Stereotape or late Ampex.  What sorts of Dolby play electronics are folks using?  I'll start with my unit, a Dolby Labs Model 330 "Tape Duplication Unit" purchased on ebay.  Any others?

Reel to Reel Tape Machines / Re: Question on Scully 280B
« on: March 03, 2007, 03:27:41 PM »
This sounds like a 14 inch reel model.  If you mount a 10 1/2 inch reel on one of the reel hubs is there still considerable clearance from the edge of the reel to the head block cover?  If memory serves when the 14 inch Scully transport was mounted in a rack the reels were up and over, and for the 10 1/2 inch reel transport the reels were side by side.  And indeed if it is a 14 inch reel model how is it mounted, that is, is it in a rack or a roll-around cabinet?  My recollection is that the decks are really heavy and hard for one person to handle.

I wonder if the tape is a late issue.  Near the end B-C gave its fans the warning that they were going dark and there was one last chance to order.  Tapes from those last days don't have the same level of quality control that was the hallmark of their earliest efforts.  In any case even for a very good B-C tape there was occasionally an audible difference, usually very slight, from side A to side B.  Also, although their literature said they used an Audiotape formulation, thankfully they changed from that early on and were using a very inexpensive Ampex duplicating formulation from the 600 series.  My experiments (on Scully 280's and RS-1500's) at the time lead me to the conclusion that while the tape had decent low level performance it had only modest headroom in the mids it had very poor headroom at both frequency extremes.  Had to keep the max. levels way down when using that tape on voice, piano, anything exposed.  Now that didn't stop B-C from making fine tapes, it just meant that they had to walk a very fine line between max. level and ultimate signal to noise when making their running master and setting levels on the dupes, and perhaps in this instance they went a bit off the line.

Service Resources / Re: Pinch Roller refurbishing
« on: February 20, 2007, 09:36:09 AM »
RE: RS-1500's
The back tension is a little weirder as there has to be a controlled slip on the large, slick capstan to keep tension in the "isolated" loop, and this involves the differential tension between the reel motors.  The service manual has full details and includes the use of a spring guage, seconding stellavox' reccomend. 

Service Resources / Pinch Roller refurbishing
« on: February 17, 2007, 03:04:30 PM »
Here is a service that rebuilds pinch rollers and other rubber parts such as idler wheels.  His address:

I just received my two rebuilt RS-1500 rollers, but haven't tried them yet. The material appears to be slightly harder than the NOS rollers (my last pair) that I just installed a few weeks ago.  The hardness may require a change in the back tension voltage when these rollers are installed.  Wonder if any others have tried this source?


Reel to Reel Tape Machines / Re: Technics RS-1520 on e-bay...
« on: February 15, 2007, 10:37:41 PM »
Just how badly messed can a deck be before you won't refurbish it.  For instance I have have a deck that I bought from a broadcast supplier for parts a few years back that's missing a reel moter and reel platform, has no pinch rollers, and it looks like sombody started replacing parts on some of the boards.  But I have had the heads re-lapped by Sprague Magnetics (now my spare headblock).  I'll bet that would not be a candidate for refurb! (??)

Prerecorded Tapes / Re: Barclay-Crocker tape catalog?
« on: February 15, 2007, 10:28:02 PM »
Actually when Barclay-Crocker decided to go out of business they sent around a short catalog that summarized all their titles and the number shipped.  Of course I didn't keep it because, well, they were out of business and there were'nt going to be any more tapes old or new.  There's a used record dealer who dabbles in (actually seels quite a bit of) reel tape and he puts the number made from that last catalog in his listings of B-C tapes, so at least one person has kept their copy.

Suggestion Box / Re: R. Strauss L.A. Phil.
« on: February 12, 2007, 12:36:11 PM »

I did read the sticky and totally blew it.  Thanks for keeping us all honest.

Suggestion Box / R. Strauss L.A. Phil.
« on: February 12, 2007, 09:10:59 AM »
1.  As it looks like there's access to early Decca stereo maybe that could be extended to the late '60's and early 70's Decca for some of the R. Strauss titles by the Los Angeles Philharmonic under Zubin Mehta.  An Alpine Symphony, Ein Heldenleben, and Also Sprach Zarathustra are still very fine performances and terrific recordings.  And of course there's the L.A. Philharmonic Planets if folks haven't heard enough of that.

2.  In many years of making duplication master tapes for broadcast automation, then making the dubs 1:1 (on Technics RS1500's) and finally running them on the air day to day I found that 10 1/2 in. metal reels are only a source of frustration.  We only used them to handle tape purchased bulk on hubs, but not for rewinding or fast forwarding.  For everything else we used 10 1/2 large hub plastic reels.  These used to made by a company called Polyline which seems to have gone by the wayside. Despite the fact that metal flanges seem to have a "cool" factor I would vote for finding a supplier of plastic reels.  The only metal reels we would rewind to regularly had 6 holes and special thick flanges, and I haven't seen anything like that in a long time.  In any case I only use plastic at home now.

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