Harman Kardon T60 Issues

[Van_Isle]

Hi folks,

I picked up a T60 today and I am having a few issues / concerns. Hope someone can lend a hand here ... the seller is willing to refund me, but I have to make a fairly quick decision here:

The table is running slightly slow. The manual pitch control can't quite get it up to speed, but I can certainly slow it down .... and hear the effect. Engaging the quartz lock slows it down further from the fastest manual setting. There are trim pots inside to adjust the manual pitch control, but there are, according to the service manual, no adjustments for the quartz lock. From what I have read online, one user who was experiencing the same symptoms, fixed their table by replacing all the capacitors on the speed control board ... although I would be surprised if contact cleaner wouldn't help at least partly.

However, I also noticed that the motor is "loose" in its mounts. The mount consists of 3 rubber bushings - each with a metal sleeve through which are mounted machine screws with both a metal and a brown-fiber washer on top. Screws are tight but they won't snug down the motor onto the rubber bushings. The service manual doesn't mention fiber washers but instead indicates that there should be the rubber bushing, metal sleeve, and felt washers. I would assume here that either the felt washers have deteriorated with time, or someone took it apart in the past and botched the job by forgetting the felts, or replacing them with the fiber washer, or perhaps even putting incorrect (too long) machine screws back in. In any case, I think this would cause the motor shaft and pulley to "lean" towards the platter ... perhaps giving an incorrect belt tension or causing the belt to ride at the wrong spot on the pulley? Or maybe its just supposed to be like this?

That brings me to the belt .... from what I have been able to determine, a Harman Kardon T60 is supposed to use a 25" belt. The belt that is on the machine is about 23.5". I tried a 25" belt with no improvement - but then the motor mount could be affecting things.

So, taking the bottom off to look at the speed control board and .... it's not the same as depicted in the service manual. I'm not surprised actually as I have a HK 430 Twin Power receiver and there are subtle differences to what is shown in the manual. The manual shows 4 trim pots for the speed control (2 for 33-1/3 and 2 for 45 rpm with the manual stating to adjust them in sequence, using the stroboscope as the guide .... looks like a coarse and a fine adjustment process). This board only has 2 trim pots (and they are not even labeled). I'm not sure what the process would be for adjustment .... by guesswork I suppose! It doesn't appear that there are any test points either ... there are with the T65c (frequency counter on test points and 1 trim pot).

I also noticed is that the foams inside the suspension springs are missing? .... removed? ... deteriorated? ... not originally there? Don't know for sure, except I have seen pictures of the inside of a T55c and it looks like the springs are wrapped in white vinyl ... and I believe I have read of the fact the springs are packed with foam. There are no pieces inside the bottom of the turntable. No foams would explain why the suspension is so .... springy!

Finally, from what I can gather, the tonearm cueing uses a solenoid so that the cueing leaver is more like a switch in operation .... it seems to work okay except when the arm is lowered near the end of a record ... then it seems like the arm moves outwards (towards the start of the record) .... the effect is it doesn't drop straight down. Hope there is just some cleaning needed there.

So, has anyone got any experience with a T60 that has 2 trimpots for the speed control? Is there someone out there who can confirm how their motor is mounted ... how loose is it? Anyone fixed the quartz lock? Are the T60's supposed to come with foam-packed springs? Anyone had issues with cueing? Any opinions or suggestions? :scratch2:

Thanks!

 

[Van_Isle]

OK I found some more info ... there is a separate T60 service manual ... I was looking at the T60C manual. It shows the 2 trim pots and the procedure for adjusting the manual speed control and it also indicates that there were 3 separate motor pulleys available for that table .... you adjust the quartz lock by checking the speed and replacing the pulley if needed ... handy!

That SM seems to show the same detail for the motor mount ... but less info in terms of parts numbering.

Nothing different it appears in terms of the springs.

 

[Pio1980]

If the motor mount bushings don't look crushed/deteriorotted they may be OK. Supposed to be a loose fit AFAIK.
Prob'ly want to do recapping first, slow running means that lightly wrapping the motor pulley to slightly increase speed is a possibility if recapping doesn't fix. Use the right belt in any case.
The springs may not have been foam stuffed. Doing so without overdoing it will reduce bouncy-bouncy but not totally eliminate it.
The substructure and bottom cover are resonant. Loosely remounting the substructure's counterweight on thin felt with fender washers will help the substructure resonances and not using the bottom cover or damping with felt and lead or Dynamat will help the bottom cover's microphony/resonance.

Properly taken care of and set up, this TT would cost around $500 or more to dupe in today's market, it's arm favors medium-to-lo-mass/higher compliance carts but folks have been known to mount less ideally matched carts with satisfaction.
You want to be sure it comes with the original mat and platter weight, it's not right without either.

 

[Aerobat]

I have a T55C with the same issues. Speed in QL is slow, speed without QL is unstable. I already replaced all of the electrolytic capacitors on both boards to no avail. Unfortunately, it's sitting on a shelf now.

 

[Van_Isle]

Thanks guys.

I found a service bulletin on the T60 regarding motor noise, which I attach here. It identifies there may have been 1 or 2 fiber washers and doesn't say felt. It also mentions bushings (brass - which I call metal sleeve in my original post) of 8.4 mm length with replacemnts being 9.4 mm. Mine are 8.8 mm. My rubber bushings appear to be in good shape. It would seem to me that longer bushings would make the motor looser.

I guess while the motor in mine is loose enough that you can "rattle" it around, looking at it again, it is kind of a moot point considering the entire sub-chassis moves around laterally in the plinth.

As I do some more internet searching, I am seeing references to foam for the springs both as an original feature and user-installed.

There is also a service bulletin attached regarding revised capacitor values for the speed board ... but my quartz lock light is not blinking.

 

[GeorgeJ]

Thanks guys.

I found a service bulletin on the T60 regarding motor noise, which I attach here. It identifies there may have been 1 or 2 fiber washers and doesn't say felt. It also mentions bushings (brass - which I call metal sleeve in my original post) of 8.4 mm length with replacemnts being 9.4 mm. Mine are 8.8 mm. My rubber bushings appear to be in good shape. It would seem to me that longer bushings would make the motor looser.

I guess while the motor in mine is loose enough that you can "rattle" it around, looking at it again, it is kind of a moot point considering the entire sub-chassis moves around laterally in the plinth.

As I do some more internet searching, I am seeing references to foam for the springs both as an original feature and user-installed.

There is also a service bulletin attached regarding revised capacitor values for the speed board ... but my quartz lock light is not blinking.

I just picked up a T60 as well a couple of months back from a local source. So far so good. But thank you for the insight and service bulletins.
George

 

[Aerobat]

Thanks guys.

I found a service bulletin on the T60 regarding motor noise, which I attach here. It identifies there may have been 1 or 2 fiber washers and doesn't say felt. It also mentions bushings (brass - which I call metal sleeve in my original post) of 8.4 mm length with replacemnts being 9.4 mm. Mine are 8.8 mm. My rubber bushings appear to be in good shape. It would seem to me that longer bushings would make the motor looser.

I guess while the motor in mine is loose enough that you can "rattle" it around, looking at it again, it is kind of a moot point considering the entire sub-chassis moves around laterally in the plinth.

As I do some more internet searching, I am seeing references to foam for the springs both as an original feature and user-installed.

There is also a service bulletin attached regarding revised capacitor values for the speed board ... but my quartz lock light is not blinking.

So how did you find the bulletins?

 

[Van_Isle]

From http://manuals.harman.com/hk/

Seems some of this stuff won't come up when you search through Harman Kardon's support web pages.

NOTE: It looks like Harman Kardon has blocked access to this route to obtain service manuals.

 

[pilotprose]

I have a T45C and had some issues with the speed, in particular, when the REFERENCE was used, the speed would "stutter" slowly going fast. I recapped the the unit and everything fell back into place WITHOUT haaving to touch the pots. I checked the speed with a hand held 60hz strobe. Got the schematic for the strobe off of Vinyl Engine, works great! Oh, on replacing the capacitors. You may find that the caps listed on the schematic are NOT the same as what are on the board. No big deal, just replace all of them and then check the speed. Clean the pots first, of course. As said, when finished recapping, the REFERENCE speed was spot on and the speed adjust was back to the CENTER position, now, that is a rarity! Took about an hour and change to replace all of the capititors.

 

[GeorgeJ]

I have a T45C and had some issues with the speed, in particular, when the REFERENCE was used, the speed would "stutter" slowly going fast. I recapped the the unit and everything fell back into place WITHOUT haaving to touch the pots. I checked the speed with a hand held 60hz strobe. Got the schematic for the strobe off of Vinyl Engine, works great! Oh, on replacing the capacitors. You may find that the caps listed on the schematic are NOT the same as what are on the board. No big deal, just replace all of them and then check the speed. Clean the pots first, of course. As said, when finished recapping, the REFERENCE speed was spot on and the speed adjust was back to the CENTER position, now, that is a rarity! Took about an hour and change to replace all of the capititors.

Nice work - If my T60 starts flaking out - I hope I can give you a call !
George
George

 

[Van_Isle]

I just picked up a T60 as well a couple of months back from a local source. So far so good. But thank you for the insight and service bulletins.
George

So do any of the things I have discussed / asked about seem different on yours?

 

[GeorgeJ]

So do any of the things I have discussed / asked about seem different on yours?

I haven't done anything other then plug mine in and clean the stylus with the magic eraser. I'm not going to open it up until I have to. But I will be looking/listening for what you mentioned.

 

[Van_Isle]

Van Alstine T60 Upgrades

I've seen a number of mentions of the Van Alstine (www.avahifi.com) upgrades to the "T" series (T25 & T30 initally and later, the T-60).

I went looking for them and initially found the index:

http://www.avahifi.com/index.php?option=com_content&view=article&id=189&Itemid=181 which indicates that the issues can be purchased.

However, if you look at the homepage there is a link at the bottom indicating all the issues of Audio Basics are available on-line free as pdf files.

So what I have found in relation to the T60 (and adaptable to others):

1. Issue 1983/09 - Test report of the T60
2. Issue 1985/06 - Silicone damping of the arm bearings
3. Issue 1985/12 - T60 External power supply
4. Issue 1986/10 - Update on the T60 P.S.

Probably also the Issue 1982/05 article on turntable damping would also be of benefit ... and I am sure there are others!

That should keep us all busy for a while!

 

[Van_Isle]

Update

I've cleaned the entire table including the platter belt rim and the motor pulley and done the deoxit thing on the speed control pot and on the trim pots and adjusted the speed. It now runs in manual mode fine. Quartz lock is still slow.

I'll be looking at a T35C as well. There is a thread going in D&S on that.

 

[GeorgeJ]

I've seen a number of mentions of the Van Alstine (www.avahifi.com) upgrades to the "T" series (T25 & T30 initally and later, the T-60).

I went looking for them and initially found the index:

http://www.avahifi.com/index.php?option=com_content&view=article&id=189&Itemid=181 which indicates that the issues can be purchased.

However, if you look at the homepage there is a link at the bottom indicating all the issues of Audio Basics are available on-line free as pdf files.

So what I have found in relation to the T60 (and adaptable to others):

1. Issue 1983/09 - Test report of the T60
2. Issue 1985/06 - Silicone damping of the arm bearings
3. Issue 1985/12 - T60 External power supply
4. Issue 1986/10 - Update on the T60 P.S.

Probably also the Issue 1982/05 article on turntable damping would also be of benefit ... and I am sure there are others!

That should keep us all busy for a while!

Thanks for all this info - I'm really liking the way my T60 sounds (especially after picking up of few GW orphans and I think these upgrades will enhance it even further (very interested in the external power supply).

 

[Van_Isle]

Up and Running

Pic of the T60 cleaned up, with my Ortofon OM5e. Not the best spot for it, that's for sure .... just temporary. I guess it's a keeper ... hopefully with all functions working eventually.

 

[Balifly]

:thmbsp: :tresbon:

 

[Van_Isle]

Here is the T35c, spinning some Lynard Skynard. Ortofon OM-20. The weight is from the T60. Now I have 2 ... hmm.

 

[Van_Isle]

HK Service Manuals

I'd given a link to the HK manual database previously in this thread. I've just edited that post - it appears that HK has blocked access to the files in this manner .... their support department informs me that they sell the service manuals. Not sure how long that has been a policy - I know I have downloaded service manuals from the main support web site previously.

 

[GeorgeJ]

Pic of the T60 cleaned up, with my Ortofon OM5e. Not the best spot for it, that's for sure .... just temporary. I guess it's a keeper ... hopefully with all functions working eventually.

Sweet! I like mine a lot: