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Author Topic: Technics RS-1520 RP-2422 Tape Head Assembly  (Read 9866 times)

Offline drmassaro

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Technics RS-1520 RP-2422 Tape Head Assembly
« on: March 30, 2008, 11:40:32 AM »
I just picked up a Technics model RS-1520 machine and it came installed with the RP-2422 tape head assembly and also came with what looks to be a new in the box RP-2224 tape head assembly.  The machine is in very nice condition.  I listened to a factory recorded 7 1/2 IPS four track tape with the RP-2422 tape head assembly in place and the sound was poor.  The sound was cutting in and out, sounded muffled and was not pleasant at all to listen to.  I cleaned the RP-2422 heads a couple of times as best I could; still the sound was still poor.  Then I removed the RP-2422 head assembly and installed the RP-2224 tape head assembly.  Now the sound is beautiful.  I have listened to other tapes with the RP-2224 tape head assembly in place and I am super pleased. 

My questions:

1.  Should the RP-2422 tape head assembly be used with factory recorded 7 1/2 IPS four track tape?
2.  The RP-2422 tape head assembly is fairly dirty on the inside where all the wires are connected.  Should I clean this area and the connectors with an electronics cleaner like the Precision Electronics Cleaner from Radio Shack?  Could this cleaner damage the heads?
3.  Anyone know what the differences are in these two tape head assemblies?
4.  If the RP-2422 is bad and needs attention, is there some place I could send it for repairs or a 'tune up'?

I am new to this forum and new to using reel to reel tapes and any help and advice would be appreciated.

Thank you, David Massaro

Offline ironbut

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Re: Technics RS-1520 RP-2422 Tape Head Assembly
« Reply #1 on: March 30, 2008, 12:32:34 PM »
The only difference between the two headblocks you have (playback wise) is where the heads are. On the 2224 the 1/4 track head is first in order (following the tape path) and the 2422 has the 1/2 track head first. The selector switch may be reversed on one or the other. As far as cleaning goes, that area behind the heads is a real dust collector. I don't think I'd worry about that but you should use some contact cleaner (I like DeOxit 5) on the switch. Just be careful not to get it on the heads. I always clean the heads after doing anything like that anyway. It's really easy to clean them when the headblock's off (be sure to clean the entire head surface every once in a while, it's easy to miss the edges when it's on the machine since the shields and the angle makes the outermost portion of the playback heads tough to get at). Get a magnifying glass of some sort to examine the heads carefully. There's a sticky at the top of the general forum that has links to what you should look for in worn heads. Use the headblock that has the least wear and use the other as a spare.
Recording wise, the 2224 will record in the 1/2 track format and the 2422 will record in 1/4 track.
Nice machine! And welcome to the forum.
steve koto
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Offline drmassaro

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Re: Technics RS-1520 RP-2422 Tape Head Assembly
« Reply #2 on: March 30, 2008, 03:14:39 PM »
Thanks for the response ironbutt.  From your response I gather that either headblock assembly should work fine assuming the headblock is in good working order.  I will follow your recommended cleaning procedure. 

I looked into the DeOxit 5 and found two types:
1.  'DeoxIT? D5 Spray, 5% solution, flushing action'
2.  'DeoxIT? DN5 Spray, 5%, 163 g, nonflammable, quick dry - non drip and safe on plastics'. 
Is one a better choice over the other? 

I checked on the web links you mentioned to better understand what to look for on the heads.  Is this the web link?
JFR Magnetics http://jrfmagnetics.com/


Offline ironbut

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Re: Technics RS-1520 RP-2422 Tape Head Assembly
« Reply #3 on: March 30, 2008, 04:54:15 PM »
I use D5. I don't know anything about the DN5 (maybe non flammable?). D5 is a good general purpose contact cleaner/lubricant. I think it's been 2 years since I treated my head selector switch and I've never had any more problems (intermittent contact). It's airborne deposits such as dust and smog that gets on sliding contacts and builds up right where you want the switch/pot to be set. Most switches/pots have a little opening on the back or side thats just big enough to get the capillary tube into/onto and give it a quick spritz. Move the switch back and forth a few times and that should do it. Some pots have conductive plastic sliding surfaces. These might be better to use that other Deoxit.
I think that JFR has a guide for detecting worn heads but this one his a good general tape deck guide with pictures of worn heads;
http://www.tangible-technology.com/machines.html
All those links have something to offer. When I started out, some were over my head but every once in a while, I'd look at them again. After a while, I'd understand this one or that one.
steve koto
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Offline docb

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Re: Technics RS-1520 RP-2422 Tape Head Assembly
« Reply #4 on: March 30, 2008, 10:55:05 PM »
The head on the bad block could be worn, but it could just be that the 1/4 track head on the bad block is out of alignment.

Re the head selector switch, take a close look at it. The little bent over tabs that hold the back wafer down get bent up and loose with time. Just take a small screw driver blade and cinch them back down so that the switch guts are less likely to move around as you throw the switch handle. Don't get too crazy, just snug them down a bit. I think you will find that solves contact issues in most cases.
Dan "Doc B." Schmalle
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Managing Director - retired, The Tape Project

Offline drmassaro

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Re: Technics RS-1520 RP-2422 Tape Head Assembly
« Reply #5 on: March 31, 2008, 10:27:04 AM »
Thanks docb and ironbut.  I do appreciate your recommendations.  I will do what you both have recommended.

Thanks again!!