Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: schturlan on March 08, 2022, 09:02:27 am
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Hi,
I have a old amp for a repair (just like the one in the picture) - for a complete potentiometer replacement.
It is 1979 PARK 50w reverb combo, and pots in it are LESA made, with specs below:
2pcs 22k log
3pcs 1M lin
1pcs 220k log
1pcs 10k log
I would like to have the amp in original state so i am searching the internet for a fit replacement pots. I also attached the pictures with dimensions, so if there is any soul out there who would like to save an amp in its original state, i would very much appreciate it.
Thanks in advance!
Yours truly,
schturlan
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Seems unlikely to me that all the pots have failed. I would clean them and re-evaluate.
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Good old Caig Dexoit D5 first, could try the lubricant after if their really bad and mechanically squeak
Here's a seller in the UK I use https://www.ebay.co.uk/itm/175127242593
1M B pots, I think that's linear, reasonable price in case your pots have truly failed
If its similar size and look you need, to make it look original, Egen and Bourns pots have a similar look and shape, and are a bit easier to find
I'm just restoring some scrap parts this afternoon, I've got a pot here that squeaks like fingernails on a chalkboard, all these pots from 1958 have come back great with good old deoxit
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Seems unlikely to me that all the pots have failed. I would clean them and re-evaluate.
I agree.
Too many people don't know how to clean them and don't know what is the good stuff; Deoxit or MG Chemical
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Seems unlikely to me that all the pots have failed. I would clean them and re-evaluate.
I agree.
Too many people don't know how to clean them and don't know what is the good stuff; Deoxit or MG Chemical
I am not a fan of cleaning since it is not a long term solution like replacing it with an unused one.
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Good old Caig Dexoit D5 first, could try the lubricant after if their really bad and mechanically squeak
Here's a seller in the UK I use https://www.ebay.co.uk/itm/175127242593
1M B pots, I think that's linear, reasonable price in case your pots have truly failed
If its similar size and look you need, to make it look original, Egen and Bourns pots have a similar look and shape, and are a bit easier to find
I'm just restoring some scrap parts this afternoon, I've got a pot here that squeaks like fingernails on a chalkboard, all these pots from 1958 have come back great with good old deoxit
Well, as i said, my first repair option is pot replacement, if i fail to find new ones i will clean them, it will be good for a certain amount of time, usually in my experience 6m-1y.
That guy on ebay sells only used pots so thats not an option, a never heard of egen, i tried to search but failed, will give it another go.
Bourns i know, but i doubt (have never seen) they have this kind of product - these old big pots with 10mm thread. Will do the search nevertheless.
I know it is hard to search replacement pots for amp as old as this one.
Do you all clean them or just replace with ones you have most easily available?
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if i fail to find new ones i will clean them
Nono
It is really a good idea to go backwards; if fail clean them, then find new ones
Why? Because old gear is usually much better made than new, why those old amp exist until today? because the parts were better! It really worth the time to clean those old pots.
Do you all clean them or just replace with ones you have most easily available?
We do clean them first, usually works just fine.
Check the videos:
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I know all about how they work, and i have a special tuner cleaning spray, i use teslanol t6 oszillin
But in my experience, they work now, but problems return after 6 month to 1 year. As i aim for high quality deliverables in my repair shop, i would rather put in NOS parts, than new ones, than after that clean old ones.
It's funny how we are all different, but that makes it fun :)
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I am not a fan of cleaning since it is not a long term solution like replacing it with an unused one.
:BangHead:
You are wrong.
Do you buy new clothes when they are dirty ? :laugh:
Pots are like your cloths, after cleaning they are like new.
That is why I wrote; "many people don't know how to clean pots......." You'll be one of them.
Like many people don't know how to wash or clean their clothes. their mom or their wife do it for them :laugh:
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I know all about how they work, and i have a special tuner cleaning spray, i use teslanol t6 oszillin
But in my experience, they work now, but problems return after 6 month to 1 year.
Because this stuff may be no good ( 1), I never heard about it, OR you don't know how to do a good job or both.
It is time for you to learn a basic job
Never see a low price stuf ( $10) doing a good job
Use a quality product if you want to do a quality job
Deoxit, the only and best one, cost 3 time more
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But in my experience, they work now, but problems return after 6 month to 1 year.
That is a good point, without adding more detail to the discussion, there are sometimes pots that get some grit inside and the track has big grooves, chips etc from bad damage, and they don't come back well at all
I have one pot in my spares that I took to pieces and cleaned manually 3 times, still has this tiny 'bump' and some clicks halfway, I wanted to keep it in an old effects pedal as it was a strange value
Teslanol looks ok, made in Germany, its all about the lubricant part of the spray, if it is good and long lasting, almost any old alcohol spray will 'clean' a pot, its that lubricant to stop it drying out and keep it feeling smooth
Its too expensive for me over here, no UK stockists to try Teslanol, only Germany
I'd like to try their rust remover though, that's something I always need!
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Our friend seems to be convinced that he has the right method despite the contrary opinions of experienced people.
He is free to insist on replacing rather than repairing.
It's a pity because it costs more to his customers.
His customers are deprived of their amp for a longer time.
And replacing parts is bad for the environment
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Guys,
I appreciate your opinions, but some of you (latole) should draw your conclusions based on facts you have at hand - which is very little at this point since you do not know me. It feels very unfriendly.
I cleaned the pots today, all are working great now. Amp has a great sound, real joy to play.
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Nice work, get it back into action, it should last another 40 years
Reminded me of this Marshall JMP service on youtube I watched last week
It was a good noise/hiss comparison before and after
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Guys,
I appreciate your opinions, but some of you (latole) should draw your conclusions based on facts you have at hand - which is very little at this point since you do not know me. It feels very unfriendly.
I cleaned the pots today, all are working great now. Amp has a great sound, real joy to play.
I recognize that some of my remarks were inappropriate and had no place here, I apologize