MRL_Audio
RIP 2022
Not sure how that fit's into a discussion about the ST-8 and ST series... but hey that's neat.
I love my Harman Kardon Rabco ST-8, But....
- Thread starter kmp14
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- harman kardon rabco st-7 st-8
Not sure how that fit's into a discussion about the ST-8 and ST series... but hey that's neat.
I worked at harman/kardon in the mid 70's to the early 80's, Rabcos were more or less my specialty. The original idea of the rabco ST (straight line Tracking) idea I believe came from an Indian engineer by the name Dipen Gohah (spl?) They where built in Plainview Long Island. If memory serves me right Rabco started with the SL-8 and SL-8E tangential-tracking tonearms, St 4 (wood cabinet with left and right opening black smoke dust cover, St 6 the econo version of the St 7 (silver aluminum cabinet, clear dust cover, then the "all new" St 8 black anodized aluminum with black smoke dust cover . The St 8 was a revised Rabco meant to be totally different. All the St 7 bugs were solved. no more rubber tracking wheel, now solid steel, upper carriage glide bar now rotates, solving the variable resistance causing tracking errors, gone was the old carburetor style dash pot , replaced with a more reliable air pot, now the St 8 had 3 belts as opposed to the earlier 2 belt systems. I also remembered I modified customers St 7's to St 8 up grades.
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frommerstop
Super Member
I used a rabco arm on a Thorens back in the early seventies. Not sure of the model number, but it used a C cell battery(!) to drive the arm. The issue I had, right from new, was that over quiet passages @ high volume, I could always hear the motor slightly through the pick-up. It would produce a low tone hum/bzzdt sort of sound. It was maddening! In fairness it wasn’t nearly as bad using a Shure cartridge, but at the time I was into Dynavector cartridges that really brought it out.
Still, it was a cool gizmo! Wonder what I did with it? Probably still kicking around here somewhere.
Still, it was a cool gizmo! Wonder what I did with it? Probably still kicking around here somewhere.
rread13
AK Member
I had a very nice condition ST8 that I sold off, I’ve still got a pair of mint ST7’s. One has had the factory upgrades, but still retains the original tire roller, and non adjustable feet? Was that normal? They both worked better than my ST8 so I don’t have any regrets parting with it, other than I really liked the platter strobe and matte upgrades.
rread13
AK Member
Reply to myself....Reflecting back on the ST-8 I do have regrets in selling mine. A lot personally has taken place over the last six years or so my life but I won't bore anyone with that! I repaired AK member Anthroscopes (Paul) ST-8 table to the best of my abilities. His table had speed stability issues, the airpot base mount bottom clip retention had cracked in places and was not holding air basically. I replaced parts on the main board and on the motor board and still had issues. I had a spare ST-7 board available , did the parts upgrades and then swapped out the boards. After doing so the ST-8 was maintaining correct speeds and my appreciation for the table returned and my regret resurfaced on selling mine. At this time Paul has his back in his possession and is getting reacquainted with it and enjoying spinning records!
I had been on the lookout for another ST-8 of which there were some popping up on eBay but all were out of my then reach in budgeting. Then a ST-5 had been offered on eBay and I zero'd in on it and low and behold it became mine. At this time I have spent some time and effort to bring this one back to proper working order; cleaning, lubricating, and still making adjustments to the overall table for tracking.
986s
Active Member
I still have my ST-5 but also now have an ST-8. The 8 is my daily and it works and sounds great. The only trouble I had was when I changed the main table belt. Tried different ones didn't want to hold speed put the original back on and speed is spot on. Thought the original belt had to be old and bad guess I was wrong. A very under rated table.
tenpiecedark
New Member
New owner of an ST-8 here. Love the look and design of it but can’t quite get the tonearm and carriage in synch. Think I’m going to have to disassemble the whole transport and start looking for the problems mentioned above. Does anybody have a link to the service manual they could post? I’ve tried all the usual places but so far have struck out. Thank you!
HalfApt
Well-Known Member
twiiii
Lunatic Member
Last year before the Munich Hi End Show I ordered and received a Dynavector XX-2 MK II. I got a special deal because the New XX-2A was just being introduced. I installed the cartridge in my Rabco SL-8E tone arm mounted on my Thorens TD 125. The sound was cleaner and clearer with extended bass and more defined highs. Which did no favors for my DG original source records. But then I started hearing all these weird noises . Especially every time the horizontal motor came on during quiet passages. So I took the arm apart cleaned all the connections and made sure I had good grounds and put it back together and there was no more motor noise from the arm. But I was still hearing a bit of rumble and what sounded like warped groove noise. So I was about to replace my Thorens with a new Technics SL 1300 G. Well thats when I go my first two DG Original Source LP's. Guess What? No more groove noise and no more rumble. OK, I just saved $3200.00. But I then pulled out my precious Sheffield Lab records that I only play very rarely as I have CD dubs for normal listening. There wasn't any groove noise there or rumble either. Thank the Heavens! So my only issue now isn't the Rabco arm , but the cheap belts Thorens is now making as replacements for the 125. I never use to have speed issues with the older belts made in the 70's thru 90's. But starting in the middle 2000 to 2010's. It would take as long as an hour for the speed to stabilize plus the belts just don't last that long as either. So a friend sent me a belt of the same length but a bit thicker and a bit wider from another manufacturer and no more speed issues. Its like having a new turntable.
I also have a Levinson VPI inspired TT that is built like a tank with a synthetic tone arm with a gimbaled pivots. The VPI tone arm has much lower and fewer resonances, but doesn't track as well as the Rabco arm. The TT is a pain to set up correctly, too. Where the SL-8E is a breeze has been my experience having installed almost 20 back in the 70's and 80's for others. Who would believe that Rabco tone arm is still working almost perfectly after 50 + years.
I also have a Levinson VPI inspired TT that is built like a tank with a synthetic tone arm with a gimbaled pivots. The VPI tone arm has much lower and fewer resonances, but doesn't track as well as the Rabco arm. The TT is a pain to set up correctly, too. Where the SL-8E is a breeze has been my experience having installed almost 20 back in the 70's and 80's for others. Who would believe that Rabco tone arm is still working almost perfectly after 50 + years.
rread13
AK Member
Is your table holding steady platter speeds? A clean brass motor hub, a clean surface on the belt, and the underside platter belt area. Has the Papst table motor "Course Speed" control pot had some contact cleaner sprayed in the opening and been worked back and forth to clean the contacts? These small things when done usually solved most speed issues. The Rabco Arm rail an carridge have to be cleaned, if you do use a lube DO NOT USE WD-40 (it lleaves a residue that dries eventually and will really cause problems later). If any lube is used I've had success with Silcone and or a Dry Teflon. The Drive Cylinder must also be clean, same with the Rabco Carridge drive wheel (the aluminum wheel). Take your time, have a clean work area, and clean hands! Let us know how things are going.
Anthroscopes (Paul) table had all of the usual treatments done but I had speed issues with his platter that you could hear variations as the record played. I had recapped his Papst motor, and recapped the ST-8 Mainboard. The speed fluctuations still persisted. The touch controls to start were only usable after a moist (licked) finger touch, his stop function did not work at all. I had a spare ST-7 mainboard that I had on hand and decided to give it a try and transplanted the two boards. The end results took an afternoon, but the results were well worth the time. Everything was working perfectly as I hoped it would and I was able to contact Paul and let him know I was satisfied I had repaired his table and he could look forward to getting it back soon and using it.