Hello from Chicago (and a Premier Ten problem)

[countfosco]

I’m a soon-to-retire government worker, Chicago area, and a 30-year C-J owner. I’m still listening to several components I assembled in 1981 as part of my first stereo system that I hope to continue to maintain. I’m somewhat handy with a soldering iron and multimeter but possessed of little theoretical knowledge of electronics.

I’ve come to the site looking for info on how to diagnose and repair my scratchy Premier Ten preamp stepped volume attenuator.

I’m tormented by crackles and pops when switching between my three most common listening levels, followed by a muffled, noisy program signal (though other levels seem for the most part Ok). Periodic De-Oxit treatments have helped a little but not enough, and not for long.

Can one simply replace that gorgeous CJ custom attenuator (with its 86 tiny resistors) with a new stock Goldpoint stepped attenuator, and exorcise the demons? Or is this a problem that goes beyond dirty contacts that likely involves OTHER replaceable components in the circuit?

There seems to be very little discussion on this board (or anywhere else, for that matter) about the Premier Ten. I’m hoping to find a schematic and a parts list for the Ten, and wondering whether its worth considering a DIY recap as long as I’ve got the hood open. Or is it best to spring for a newer model?

I appreciate archives access and any advice you may have!

*****
System A: Martin Logan Spire, Hafler/Musical Concepts mod DH-500, Conrad Johnson Premier Ten, Clearaudio Nano, Clearaudio Concept, Marantz CD-6007, Sansui TU-919, Nordost Heimdall

System B: Spendor BC1, Hafler/Fantasia mod DH-200, Conrad Johnson PV-2, Bang & Olufsen Beogram 4004, Sansui TU-717, Nordost Blue Heaven, Monster Cable

[admin]

First,
Welcome to CJO, gret to have you with us!

If the De-Oxit has not resolved the problem (but did improve it), most likly the volume control with need to be replaced. I honestly don't know if that particular part is still made, and CJ does not sell parts.

So you have two choices:

1) Send the unit in to CJ headquarters to get a full repair and diagnosis.

2) Find a 3rd party volume attenuator and replace it yourself.

The 2nd option is obviously the cheaper one and if you are handy with a soldering iron it could be a very reasonalble DIY project. Of course there may be some other issues going on as well as the Premier 10 is no spring chicken.

BTW- Nice gear. I'm a big fan of Martin Logan and owned their Vantage speaker for a number of years. CJ sounds great with planar speakers.

[roberto]

Hola and welcome.

Regarding the stepped up volume attenuator, you can find it at Ebay.com. As far as I know, CJ never used in their components a stepped up attenuator. It might be changed by the first owner. I don't find any problem using it. What bugs me is that you are having noises while using the one that you have in your preamp. Why don't you clean it with an electric contact cleaner?

In Amazon:

https://www.amazon.com/Hosa-D5S-6-DeoxI ... 158&sr=8-4

Nice system. Hafler is one of the best SS amps. It uses Vertical FET at the output stage. David Hafler did a great job designing it.

Happy listening!

[AnotherJohnson]

From the owner’s manual
**********
The volume control is a 23 position switch selecting among 23 pairs of resistors ­ never more than a single-pair of resistors are inserted in the signal path by this control. The balance control is an 11 position switch that is electrically out of the circuit in the centered position. There are no carbon-track or conductive plastic resistive elements to degrade the audio signal in the Premier Ten.
***********
Sounds unique. A forerunner of the ladder style we see today?

[roberto]

Oooooppppssss, sorry, my big mistake.

Anyhow, you can clean the control applying the fluid and moving the knob once the cleaner is applied. The remain fluid will evaporate and you might have a new control after the cleaning process.

Happy listening!

[countfosco]

Thank you for your warm welcome and helpful suggestions!

I’ve decided to take the frugal approach and De-Ox the attenuator contacts one last time. (There are nearly a hundred resistors that make up the ladder-type stepped attenuator in the Premier Ten, along with a hundred contact points to be cleaned - I’ve had to do this a couple of times in recent years.)

This time I followed the advice of a hobbyist on YouTube who was extolling the merits of applying De-Oxit Gold to electrical contacts, after an initial flush with old standby De-Oxit 5, for longer-lasting protection. While I was at it I checked that all caps were in spec, changed out the four tubes, and cleaned up a couple of dubious solder joints.

I was rewarded with that familiar velvety-black silence between and beneath musical passages that we’ve all come to expect, and that I've been missing for too long. But with two electrical contacts in the signal path, I think that the stepped-ladder type of control that was used in the Premier Ten is inherently noisier than the newer “series-type” designs used today with only a single contact, and it is naturally prone to pops and clicks. I’ll see how long the De-ox treatment lasts, but I expect that one of these days I’ll be replacing the volume attenuator with a more modern design that incorporates low-noise surface-mounted resistors. I'll let you know how that goes.

And yes! I’ve been very satisfied with using a CJ tube preamp along with a powerful solid state amp to drive the electrostatics. Thanks again!

[Big Dog RJ]

Good stuff matey!
Glad to hear you found a viable solution and now you're back, enjoying those fine tunes!

Please do keep in touch.
Woof! RJ

[admin]

Good to hear. Enjoy the tunes.

[roberto]

Thank you for your warm welcome and helpful suggestions!

I’ve decided to take the frugal approach and De-Ox the attenuator contacts one last time. (There are nearly a hundred resistors that make up the ladder-type stepped attenuator in the Premier Ten, along with a hundred contact points to be cleaned - I’ve had to do this a couple of times in recent years.)

This time I followed the advice of a hobbyist on YouTube who was extolling the merits of applying De-Oxit Gold to electrical contacts, after an initial flush with old standby De-Oxit 5, for longer-lasting protection. While I was at it I checked that all caps were in spec, changed out the four tubes, and cleaned up a couple of dubious solder joints.

I was rewarded with that familiar velvety-black silence between and beneath musical passages that we’ve all come to expect, and that I've been missing for too long. But with two electrical contacts in the signal path, I think that the stepped-ladder type of control that was used in the Premier Ten is inherently noisier than the newer “series-type” designs used today with only a single contact, and it is naturally prone to pops and clicks. I’ll see how long the De-ox treatment lasts, but I expect that one of these days I’ll be replacing the volume attenuator with a more modern design that incorporates low-noise surface-mounted resistors. I'll let you know how that goes.

And yes! I’ve been very satisfied with using a CJ tube preamp along with a powerful solid state amp to drive the electrostatics. Thanks again!

Those Spire are great sounding speakers.