Inherited Carver Stack Troubles

[ProAlpine 8]

Greetings. Thanks for the add. My dad owned a burglar and fire alarm company from the 70s - early 90s. In addition to installing alarms in high end homes, he installed Hi Fi on the side. We always had a bitchin sound system in the house growing up. I remember him playing discs (not compact, but the size of vinyl) way back in the day. Then we had CDs way before most even knew what they were. Well he passed away a few years ago and I've come across some of the stuff...

 

Like others, I inherited my dad's carver stack: C-2 preamp, M-1.5t amp and m-200t amp. They haven't been used in many years. I'm wanting to hook up a Pioneer record player to listen to vinyl in the house. 

 

First, some guidance on connecting everything up would be great. Can I use both the M-1.5t & the M-200t? Or is it one or the other, not both. If that's the case, which do you suggest?

 

Next my volume control seems corroded. I've tried spraying CRC Electronic Cleaner and turning the knob, but it's ineffective - lots of cracking and R speaker comes and goes. Should I try something else? Is there a replacement?

 

Thanks for the help.

[Balok 1,604]

If you have cleaned the volume pot and it still crackles or you have channel drop out you probably need to clean the balance pot. I am no expert, but I use fader lube on pots and contact cleaner on switches.  Both caig deoxit. 

[3M_Audio 1,800]

Welcome!

 

Since you found two amps I'm guessing your dad used the bigger amp (1.5t) for the 'main' system and the 200t for a second room? But if you're only working with one room, the M-1.5t should do the job nicely. But either should be fine if it meets your power output needs.

 

For the volume control, in some cases it's hard to get the liquid into the pot for cleaning. If the CRC doesn't change at least reduce the crackling, I'm guessing it isn't getting into the wiper of the pot. If you are comfortable with removing the cover so you can get direct access to the pot, a straw on the CRC sprayer should be able to get the cleaner in there. Look for a little opening/notch in the pot body to allow access. Spray it with power off (and the system unplugged and sitting for 5+ minutes), rotate the pot fully back-and-forth 4-5 times, then reconnect everything and try again. 

 

And @Balok had a good insight as the Balance pot can also get distortion into either audio channel. In fact, if you've gained access to one pot, it's a good idea to clean them all.

 

Good luck.

[Eyexlr8 90]

That is a problem for many sealed pots. Simply no way to get to the  tracks to clean them.

This PSE studio 1 had 3 expensive noble cast aluminum pots ,2 in the tone control circuit plus volume

The balance control had a open area on the side for access but in most cases you have to unsolder

many pots and take them apart and open them up to do it properly

[Cring08 224]

Welcome!

[ProAlpine 8]

Thanks for the insight folks. I have taken the cover off and sprayed the electronic cleaner on the backside of the volume control and swiveled the dial repeatedly to no avail. It's still full of crackle and poor sound. 

 

Excuse my ignorance, but is a pot the dial controls for volume, balance, etc?

 

And from what Eyexlr8 has suggested, these pots are sealed? So I'll need to unsolder them to take them apart and clean them? Arg... looks like more youtube videos (if I'm lucky there are any) in my future.

 

Cheers

[AndrewJohn 10,010]

On 4/25/2024 at 12:54 PM, ProAlpine said:

First, some guidance on connecting everything up would be great.

 

Welcome, @ProAlpine, glad you found us.  This website is a great forum of information and active fans - and it's searchable..., lots of historical information.

 

As for this first request, I think the best way to approach this is to pull down the manuals for the C-2, etc., that you have.  The configuration and wiring diagrams on how to hook things up are pretty good in the original manuals. 

 

You can find the manuals for download, at the top of the homepage for the website, in the "Manuals and Specsheets" pull down menu.

 

Again, welcome!

[3M_Audio 1,800]

14 hours ago, ProAlpine said:

Thanks for the insight folks. I have taken the cover off and sprayed the electronic cleaner on the backside of the volume control and swiveled the dial repeatedly to no avail. It's still full of crackle and poor sound. 

 

Excuse my ignorance, but is a pot the dial controls for volume, balance, etc?

 

And from what Eyexlr8 has suggested, these pots are sealed? So I'll need to unsolder them to take them apart and clean them? Arg... looks like more youtube videos (if I'm lucky there are any) in my future.

 

Cheers

 

Yes, the dial controls in most audio equipment are potentiometers and commonly referred to as simply 'pots'

 

Pots will generally be sealed to try and keep dust out, but most inexpensive pots still have some small openings where you can get in some cleaner. Here's an example - the straw on your cleaner can sometimes sneak in a little opening like where the red arrow is (and sometimes there are small openings on the back):

 

 

The better pots are usually sealed to keep all dust and dirt out. These usually are meant to be replaced when they have a problem, but if you're skilled like @Eyexlr8 is, you can often carefully disassemble and clean them. Here's a completely sealed pot for comparison to the above:

 

[Rob 5,288]

 I kept my volume pot when I upgraded my C2 with a motorized/remote control volume. You are welcome to have it. But there are many access points open that pot to get some cleaner in there. 

 

 

 

Edited April 29, 2024 by Rob

[Rob 5,288]

[Rob 5,288]

Here is a thread you can check out on the C2

[Eyexlr8 90]

These cheaper and smaller volume controls usually have poor channel to channel tracking due to the smaller carbon track and smaller wipers

in comparison to the bigger blue Alps pots. If you have the room for it I would replace it like Rob has done

You can also carefully bend the tabs back and take it apart for inspection and sometimes they just go bad since these have the highest mechanical wear in the entire electronic food chain

[Kurt 2,512]

Welcome to the site!  Glad to see you are getting the advice you sought.  Good group of folks, here :).

[ProAlpine 8]

Well, I've tried and tried and still no luck. I ordered the Deoxit and tried squirting it into the tiny hole on the side of the pot, with vigorous turning of the dial but still horrendous sound when I turn it on. 

 

Probably need to replace the pot or disassemble and try and clean??

 

[Ar9Jim 6,504]

3 hours ago, ProAlpine said:

Well, I've tried and tried and still no luck. I ordered the Deoxit and tried squirting it into the tiny hole on the side of the pot, with vigorous turning of the dial but still horrendous sound when I turn it on. 

 

Probably need to replace the pot or disassemble and try and clean??

 

Is the noise happening at idle while sitting still or just when you move the pot?

Edited May 30, 2024 by Ar9Jim

[ProAlpine 8]

17 hours ago, Ar9Jim said:

Is the noise happening at idle while sitting still or just when you move the pot?

Great question! 

 

Both. The noise is at idle, any volume and when adjusting the volume...

[oldtexasdog 2,430]

Some faulty caps or resistors or bad solder joint maybe??

 

[Rob 5,288]

Have you cleaned any of the selector switches? I had some noise issues and it turned out to be the input switch. 

[ProAlpine 8]

Hey team, I've hit the wall trying to clean the volume pot. I've had no luck. If Rob or anyone else has a volume pot they'd like to sell please let me know.

 

Thanks

[3M_Audio 1,800]

You mentioned in reply to @Ar9Jim that you would get the distortion at idle while sitting still and when adjusting the volume. That may indicate that the issue may be more/other than the pot. As cleaning a dirty pot as you've now done is pretty often successful, perhaps it's time to get the whole unit to a skilled shop for repair? An added benefit is that you could also have the whole unit checked against spec, service bulletins applied, and any questionable components replaced so that you could get many years of enjoyment from it.

[ProAlpine 8]

18 hours ago, 3M_Audio said:

You mentioned in reply to @Ar9Jim that you would get the distortion at idle while sitting still and when adjusting the volume. That may indicate that the issue may be more/other than the pot. As cleaning a dirty pot as you've now done is pretty often successful, perhaps it's time to get the whole unit to a skilled shop for repair? An added benefit is that you could also have the whole unit checked against spec, service bulletins applied, and any questionable components replaced so that you could get many years of enjoyment from it.

That's probably the best course of action. Thanks for the suggestion. Now, to find a reputable service shop that's not too far away - I live in a small town... 

Thanks again.

[AndrewJohn 10,010]

52 minutes ago, ProAlpine said:

Now, to find a reputable service shop that's not too far away

 

Most of us just deal with the added cost required to "ship" it.  On average, shipping a Carver component across the country is about $50-60 with FedEx.

 

Why?  Eliminate two risks..., 

 

Risk 1.  There just aren't very many reputable electronics ships around anymore, especially if you are in a rural area.  And, you gamble on getting your unit broken worse, by an inexperienced tech - or worse, one that doesn't know much about Carver designs - they are unique, and someone that can fix, say, a heathkit amp, or traditional receiver, is going to be over their head with Carver designs.

 

Risk2. YOU control the quality and robustness of packaging your unit for shipment.  so you know it's handled properly, and going to survive a 6' drop off a conveyor at FedEx - because YOU packed it in solid sheet styrofoam, and a double-box.

 

the two that most here know of are: Nelion Audio (www.nelionaudio.com) in West-central Michigan and Rolland Barr, on the west coast.  These two are independent, and have years of experience, as well as Bob Carver's endorsement.  They ONLY do Carver work (or primarily) so they don't have to "figure it out"..., they understand the unique designs Bob implemented to generate great audio, and can put the units back in shape.

 

There ARE of course, other techs out there - both with experience, and up and coming gaining experience, and you should consider those too...

 

Best of luck on your next steps.