Your conclusion is related to what I found with the Shamrock tape in the
Racal deck. Jay McKnight had suggested a faster speed, but that did not
work on the A810, but did on the Racal. Less tension, I suspect and a
"sharper" head profile.
I'm glad you found this! Another tool for reacting to problem tapes.
On 2014-02-06 4:28 PM, Shai Drori wrote:
> Dear Richard, Paul and everyone else.
> Okay, here's what I think and what made me think about it. The tapes do
> not need baking, they do not show any signs on hydrolysis. SKC is a
> Koran brand that makes pretty good tapes on the lower end (TDK d, Sony
> HF, TDK SA, etc). They can sound very nice and their chrome tapes
> reached -1db at 19.5kHz on my auto bias deck. I have never had tapes
> from SKC squeal before so I played them in different decks for ingest
> and found that they squealed in all decks except the RX-202. This
> includes other decks that are single capstan as well.
> The RX-202 is a single capstan design that relies on the felt pad for
> head contact. I can try to change the shell and slip sheets but I
> suspect the tape has dried up a bit. What I think makes it play in the
> RX is the head geometry that is more cone like rather than curved. I
> think it makes for a shorter head area that is in contact with the tape
> and at a sharper angle of attack. The MR-1 (cr-7, dragon, 680, etc, have
> more curved heads.
> I tried to play the tape in a closed loop (several machines) and it
> squealed in all of them. I think the closed loop makes a tighter tape
> that resonates faster because of higher tape tension on the head. BTW,
> the RX might not be a Dragon but it's a very good player. If I could
> only disable it's "skip unrecorded end" where it FF if it thinks there
> is nothing recorded, it would be perfect.
> בתאריך 06/02/14 9:28 PM, ציטוט Richard L. Hess:
>> Hi, Paul,
>> I'm sorry for all the details, but this was a real gestalt for me.
>> In general, when a cassette squeals in the Nakamichi Dragon, the only
>> thing that helps is lubrication with D5. That was why I was so excited
>> by Shai's "discovery" as it provided a whole new perspective on
>> potential causes and cures.
>> Generally (and I'd love to hear Shai's answer with this specific
>> tape), placing the tape into a new shell has had no effect. That
>> bypasses the slipsheet question and the hub-to-shell friction.
>> So, thanks to you and others who mentioned slipsheets as that is
>> important. I had a cassette that would not play for a client and I was
>> able to make it play, and slipsheets were part of the issue--the ones
>> that came with the tape were all wavy and horrid. The other part was
>> minor layer-to-layer adhesion, but not enough to pull off mag coat.
>> I do not know what caused the adhesion, but I would not be surprised
>> if it were some exudate from the decaying slipsheets.
>> On 2014-02-06 12:20 PM, Paul Stamler wrote:
>>> After Richard's detailed discussion I'm hesitant to jump in with an
>>> elementary-level question, but here it is:
>>> Shai, have you replaced the slipsheets in the squealing cassettes?
>> -- Richard L. Hess email: [log in to unmask] Aurora, Ontario,
>> Canada 647 479 2800 http://www.richardhess.com/tape/contact.htm
>> Quality tape transfers -- even from hard-to-play tapes.
-- Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada 647 479 2800
http://www.richardhess.com/tape/contact.htm Quality tape transfers --
even from hard-to-play tapes.