[audioenthusiast]

Hi,
I've just bought a TAG Mclaren 60i in the classifieds. It hadn't been used by its previous owner for a few years, and he had no facility to demo at this house. So I paid a deposit and took it for home trial (to check it works properly, not to check I was happy with the decision of a 60i).
Something has come up, please could somebody tell me if it's normal, purely a superficial problem, or something that's likely to develop into an actual problem?

The issue that I'm seeing is that the bottom 10% or so of the volume control feels rough and gritty.
I know that the volume control 'going' is fairly common on older amps, and can lead to crackles. There's a definite jump between rough and smooth - it doesn't just lessen as you turn it up.

Does it sound like I'm going to get a crackly amp in a year or two? Or is it likely to stay exactly as it is? Or, in fact, do TAG amps feel different in the bottom section of the volume control?

Currently it sounds fine so not a problem if it isn't the start of a bigger fault.

If somebody can post some thoughts ASAP that'd be great, as it's holding up the resolution of the trade.

Thanks in advance.

[BlueWizard]

Feels rough and gritty or sounds rough and gritty?

Someone has posted a video in your other thread indicating how to clean volume controls. But I would not follow that advice until I was sure it was the actual control itself.

If it currently sounds OK, then it is probably not the volume control itself. It could very well be a mechanical problem. First see if you can remove the volume knob. Frequently this is done by loosening a couple of very small set screws in the knob.

It is possible the some general crude/dust/lint/whatever has built up on the mechanism or the shaft. That can be easily cleaned away with a brush or in worst case with some Isopropyl Alcohol.

Also look inside the amp, it is possible that the knob you turn is not directly attached to the actual volume control. It could operate with some type of gear or pulley system. Again, if this is true, and if the amp does not crackle or make a static sound when you turn the knob, the problem is most likely mechanical.

I would not open the volume control itself except as a last resort.

I'm not there I can see the amp or feel the control, so there is a limited amount I can say. I have opened sealed volume controls and cleaned them, but I don't recommend it to the average user. Also, you need the proper cleaner to clean the control.

If you are not hearing a crackle or static when you turn the control, then I would not open the control itself. Most likely this is some external problem related to dirt/lint/dust or general crude.

Steve/bluewizard

[audioenthusiast]

Thanks for the input Steve.

It sounds fine - I tried moving it over the rough section while turned on. It's purely a 'feel' thing for now, but I was just worried about it becoming a sound thing later on. But right now, no crackle or anything.
Good news if it isn't the actual volume control, in that case.

Based on your thoughts I'll have a look at it tonight but definitely not disassemble the volume control - I wanted to avoid that as I suspected it's a high-precision part.
Seller has given permission for me to open up the case so I'll see what's going on.
If I cant fix it with some cleaning and dusting, I'll post some photos of the inside.

[Jimholt]

Not sure whether you mean the actual volume knob is gritty when turned or whether the sound is gritty. If its the sound when turning up the volume and it stops making the noise when stationary, it is more likely dust that as settled. I had a Sony amp which had sliders and that was the same. You could try giving the volume a good few turns up and down to see if it ceases.

[canavan]

If it's just a rough feel, then it's possible that the volume knob is slightly off-center, and the rough painted exterior is rubbing against the fascia. With a AV32R, you can just carefully pull off the knob, re-center the rotation sensor thingy (that's probably a potentiometer in the 60i, but I suspect they both have the same kind of shaft) and possibly tighten up the nut that holds the potentiometer in place a little. The whole mechanism is built to be adjustable, so it should be no surprise if it goes out of alignment.

[audioenthusiast]

Thanks for the tips guys, I haven't forgotten about this thread.
I haven't managed to get hold of a screwdriver for it yet - with all the lovely weather recently I've taken the decision to do the garden properly this year! I will get on it soon though.

I have noticed something about the gritty feel though. It's nothing to do with the angle of the knob at all, but actually to do with how I apply force as I turn it. It turns out that as I turn it up or down, I end up putting a very slight upwards force on it in the first few %. This is what is causing it to grate. (or it could have been downwards, I can't remember now).
If I'm very careful with turning, I can stop it from happening. And I can intentionally make it happen at any point on the dial by re-applying the force.

So I guess that supports the theory that it's just the knob grating against the front panel, and not the pot at all?

[audioenthusiast]

I know this has been a while, but just to update the thread...

I finally found my screwdriver set with the star heads. I took the cover off the 60i, and the problem went away. So I guess it is the knob rubbing against the case. I put it back together and couldn't align things any better so it didn't rub. But knowing that it's just a cosmetic issue, I'm happy to leave it.

I then went round to a friend's house to help install my old 5.1 set I've sold him, and left the screwdriver set round there! Really handy set, but I just can't seem to hang onto it for more than 5 minutes