Which amps are the hardest to get parts for?
- Thread starter 6mantoys
- Start date
Superampman
AK Member
Oh stop it! Nothing like instilling fear into the newly initiated, eh? The right tech will not only fix it but most likely improve it. Hard to find? OK. Impossible? NO
Brian
An Old Geezer
There is a difference between inflicting fear and a dose of reality. The opinions asked for some reality. Some parts are just no longer available though one can hack something together. Many volume controls, especially those with power switches on the back that are full sized. Power transformers, output transformers, dial glass, switches with glued on knobs like a number of toggles, dials off those beautiful HH Scott tube tuners and the list goes on forever. Only sourcing is from donor units. I had to wait a year to find a parts unit to get a dial glasses for my Sony STR6120. Some parts just can not be sourced and there are no donor units. Look for a Marantz 9 removable plate or even a replacement 10b scopetube.
One of my Sherwood S3300s uses a Microcircuits, a predecessor to the LSI and IC. New ones are just not obtainable and replacements likewise. So far it seems no one has found any way to mod the unit to accept an ic. It looks like a transistor with a load of leads. Try to find the front end for Fisher TFM1000. Or, I.F. Coils for Sherwood tube and early SS tuners and receivers. I suspect as easy as new filters for the 10b. Or, the multiplex coils correct the Sony STR6060.
The PECs I mentioned in my post were popular for a relatively short time. In a number of units they are detailed in the SM while many are not and if they go out of try to get a replacement discrete component replacement engineered.
This is not to say one should be scared off but know what to look for. I applaud the op in asking the question as it can really help to know the temperature of the water he is jumping into.
vinylisfinal
Super Member
Bozak amplifiers... parts are scarce
Vinylcafe
Linvin' the Dream
+3 on any amp with VFETs.
Not only do you have to find them, but you have to find the correct ranking.
If you cannot find the correct ranking, you need a whole new set, all with the same ranking (per channel) .... so you need to find more of an already rare thing.
And if you do find them, they are spendy.
GD70
Lunatic Member
JVC M7050 power amp. Some parts are available, physical ones like face glass, proprietary Super A modules, and who know what else probably not. Like said before, I need a donor amp. Good luck with that!
I had to have a glass shop make me new face glass. It's not perfect, but it will due and looks good.
I had to have a glass shop make me new face glass. It's not perfect, but it will due and looks good.
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ConradH
Lunatic Member
If a design is conventional but they used some oddball ICs, you can often design a work-a-round. Sometimes you can transplant an entire new circuit- some tuner sections come to mind. If they did something completely different/unknown, like the stupid analog modules used in ARC solid state preamps and power amps, you may be SOL unless you can do some major redesign work.
There are some transistors and MOSFETs that can't be had, but the amp can almost always be convinced to work (and work properly) with something else. Then you have to decide if those parts really made a sonic difference, or were mostly marketing or specsmanship. The Sansui (Sanken) high speed outputs are like that- do you really need an audio amp with MHz bandwidth capability?
Some parts are described as hard to find, but are still around if you search a bit. The old IC (uA739?) used in the Crown DC-300A is one of those. You do have to watch out for counterfeits.
Controls are a huge issue because little in the modern electronic world uses pots, much less pots with loudness taps, anymore.
I have the biggest problem with cosmetic stuff. Anybody got a spare rack handle for a Crown PS-200? Tone knobs for my Sansui 2000x that don't cost $24 each? How about a laser module for my Kyocera 710cx player? Well, I can always hope.
There are some transistors and MOSFETs that can't be had, but the amp can almost always be convinced to work (and work properly) with something else. Then you have to decide if those parts really made a sonic difference, or were mostly marketing or specsmanship. The Sansui (Sanken) high speed outputs are like that- do you really need an audio amp with MHz bandwidth capability?
Some parts are described as hard to find, but are still around if you search a bit. The old IC (uA739?) used in the Crown DC-300A is one of those. You do have to watch out for counterfeits.
Controls are a huge issue because little in the modern electronic world uses pots, much less pots with loudness taps, anymore.
I have the biggest problem with cosmetic stuff. Anybody got a spare rack handle for a Crown PS-200? Tone knobs for my Sansui 2000x that don't cost $24 each? How about a laser module for my Kyocera 710cx player? Well, I can always hope.
Superampman
AK Member
I was kidding about the fear part. I suppose you're right. I can't relate though. I have a lot of vintage power amps and no receivers.
jeromach
With sufficient thrust, ducks fly just fine
jeromach
With sufficient thrust, ducks fly just fine
I guess there's a difference between the tech parts and the cosmetic stuff; without the proper tech parts it might be impossible to get an amp to work, without the proper cosmetic parts it might still do the job perfectly.
I wonder if the the 3d printers will come to help soon, for instance some knobs of 70's Technics gear are of a kind of blackish plastic that deteriorate over time, but it must be possible without too much effort to create these with a 3d printer.
What I regard as future doorstops are all amps containing STK/SVI modules, unless someone engineers a workaround. To me it doesn't seem impossible, but it might not be worthwhile financially.
I wonder if the the 3d printers will come to help soon, for instance some knobs of 70's Technics gear are of a kind of blackish plastic that deteriorate over time, but it must be possible without too much effort to create these with a 3d printer.
What I regard as future doorstops are all amps containing STK/SVI modules, unless someone engineers a workaround. To me it doesn't seem impossible, but it might not be worthwhile financially.
ConradH
Lunatic Member
I just read that Staples is going to have 3d printers in the store. Don't know if they have Staples in the Netherlands. It would be really neat to design a knob or something on the computer, email it to Staples, then drive over and pick it up in a few hours, or just have it mailed.
Brian
An Old Geezer
The PECs I mentioned in the first posting mostly apply to the preamp/power amps. Controls such as full sized volume, in combo with the power switch and loudness contour likewise as well as the independent ganged controls used for separate volume and tone adjustments. A power amp should be a very simple design in concept; look at units like the McIntosh MC250 and 2100 but companies I guess realized to sell at high prices some unit with so few parts does not make marketing sense so dump all kinds of needless circuitry into them.
Preamps likewise need not be the complex animals many are to actually do a good job. In fact sometimes the marketing department demanding 1,000 switches and knobs to make the unit look impressive may make it a sales hit but underperforming in terms of potential quality. Tuners are similar in this regard. A well designed 3-gang, with minimal i.f. stages may not be the dx king but may sound better than a 5-gang tuner with 4-8 pole filters that make it a killer dx'er but at a cost of sound.
Brian
An Old Geezer
An article in the local paper recently was about the Toronto Public Library starting a project to iinstall 3d printers in the libraries. I guess they need some reason to get people in as more and more reading is done from digital sources. They also for years have had wifi and have been increasing in-house computer stations.
