Proton anyone?

[62caddy]

Just hope and pray you don't have to clean the dreaded scratchy pots on the D940. I forget which ones, but a couple of them are buried in the back under a board with extensions to the control face. I think I had to open mine up 4 or 5 times before they were finally clean.

When I bought my first Pioneer I opened her up to clean the pots and was delighted to see I had room to work and the pots were within easy reach.

I've never had any problem with the pots on my D940- perhaps because I use them often; the input/record selectors however are another story. I usually have to "half-index" them to get it to play both channels- not a big problem. Otherwise it's been a great receiver for 20+ years with never so much as a hiccup. And I've never been able to get the DPD light to go on- no matter how loud and with 2(!) pair of 8 ohm speakers.

 

[dosmalo]

1,200 watts into one ohm?

If I remember correctly, when Stereo Review's Julian Hirsch tested the Proton D1200, it put out 1,200 watts into one channel at one ohm.

But how stable was it? This couldn't have been a "real-world" situation. Most power-house amps won't do a one ohm load. That's murder.
Julian must have been doing a bench test.

 

[Pyrrho]

... Very under rated amps IMO. ...

Proton made several amplifiers that had an incredible peak power output capability. But they cannot deliver that power continuously, so they are not that underrated for continuous power. My electronics technician brother has repaired several Proton power amps that were owned by people who did not appreciate that fact, and ran them too hard for too long and burned them up.

 

[62caddy]

Proton made several amplifiers that had an incredible peak power output capability. But they cannot deliver that power continuously, so they are not that underrated for continuous power. My electronics technician brother has repaired several Proton power amps that were owned by people who did not appreciate that fact, and ran them too hard for too long and burned them up.

You can burn up pretty much anything if its mistreated badly enough. High continuous power is not necessary for the majority of most applications; however musical peaks of very short duration will require much more power and that's where Proton/NAD and a number of other manufacturers excel in their ability to deliver these peaks cleanly. It's also more economical but if one insists on ear-splitting volume, (and price is no object) then absolutely yes- large powerful amplification would be necessary.

 

[Pyrrho]

You can burn up pretty much anything if its mistreated badly enough. High continuous power is not necessary for the majority of most applications; however musical peaks of very short duration will require much more power and that's where Proton/NAD and a number of other manufacturers excel in their ability to deliver these peaks cleanly. It's also more economical but if one insists on ear-splitting volume, (and price is no object) then absolutely yes- large powerful amplification would be necessary.

Yes, I am not saying that there is anything wrong with Proton power amps. I am just saying that their incredible peaks are just peaks, and not continuous capability. And just because the meters can read those peaks, that does not mean that one should run it anywhere close to them for any length of time. In fact, with the Proton amplifiers that have unusually high headroom, one must keep the average power output far from those incredible peaks or there will be trouble.

 

[DaLarry]

Boy, it's a small world. Proton is a Taiwanese company. I used to do legal work for them back in the mid '90's. I was pretty tight with their CFO and President back then. They had a warehouse either in Diamond Bar or Rowland Ht's in the San Gabriel valley, east of LA. I had a lot of their stuff, including a gorgeoous TV. They always wanted to pay me "in kind."

 

[Dan D.]

Damn, this Proton bug bit me a vicious one tonight. I just couldn't help myself. I used to salivate over the Crutchfield catalogs in college, and for whatever reason the Proton goodies really grabbed my attention. 20+ years later I now have an RS 325S alarm clock radio, an AM 300 amp (broken) and an AM 455 amp all on the way to my front porch. And that's only the first night of shopping. What are the chances I will regain my sanity? This is more addictive than I thought.

 

[62caddy]

My D940 had been sitting unused for a little under a year. I began getting it ready to list on ebay but just to be on the safe side I decided to give it a test run before I declared it perfect. Much to my chagrin, I discovered the tuner display is now not functioning correctly. The tuner preset and scan functions perform normally, the digital display will not reflect changes made to the tuner frequency settings- and remain unchanged. Toggling back and forth between AM/FM many times seem to eventually call up the correct numeric frequency. Also the display will show a decimal point for AM and none for FM at times. Now my question: any suggestions as to if I should get the unit repaired before offering for sale or simply offer AS-IS? Everything else works fine and the unit is mint with original receipt, owner's manual, AM loop antenna, original Proton literature, Proton's "white paper" detailing the DPD amp's performance and test report from Audio (8/86). I'm assuming something is up with the IC programmer chip. My fear is that with the malfunction, the unit will bring next to nothing but it is really such a nice unit, I simply cannot bring myself to give it away for nothing. Any suggestions from somebody who has some degree of technical knowledge as to what may be involved would be tremendously appreciated.

 

[js1138]

Protons are noted for cold solder joints and susceptibility to dirty controls.

Is it possible to unplug and replug the cables connecting the display? That's what you do with computer cards that misbehave.

 

[62caddy]

I tried unplugging the unit from the wall. Does that count? Seriously though- is this something that one with no experience working on electronics can do himself?

 

[Dan D.]

I tried unplugging the unit from the wall. Does that count? Seriously though- is this something that one with no experience working on electronics can do himself?

I'm about to take the plunge on my first DIY repair on an old Philco tabletop stereo (if I lose the patient, it will be sad, but not life-altering) If you have the bug and want to learn, this forum is a gold-mine of info and procedures. I've picked up a few injured Proton pieces recently and plan to have a go at those after the Philco. It's a gamble, but learning about this subject is the ultimate goal for me. Just think of the smile you'd have if you try the repair yourself and it WORKS! If not, there are people who can do it..for a price though.
Either way, I hope it's something simple and minor in your case, it sounds like a really nice piece.
Dan

 

[DCinDC]

Old thread I know...

I love Proton gear!

I had the DPD75 in my trophy winning Mustang GT driving a subwoofer. Sadly it was stolen.

I have the AV preamp still.

I had their 19" TV and everything they said about it was true. It had a FANTASTIC picture due to them paying particular attention to the dynamic range of the drive circuits. I found it in the trash and after months of clueless troubleshooting I found a sand resistor open in the AC line. This was long ago and I was not a good TV tech.

It took 20 more years for a TV to displace it at the top of the heap for picture quality. That was a 27" Sony Wega (the Made in Japan ones, not the newer Chinese stuff).

I've always lusted after the 1200 amp. Georgeous meters!

I've had several of the clock radios. They usually just need capacitor replacement to function properly again.

The Schotz tuners were the best I've heard for making a bad listening situation tolerable. I mod'd them with better filters and output amps, and they are giant killers in actual use. They are susceptible to shipping damage though, and the front panel anodizing tends to fade. Still, it's one of my favorite tuners.

and 62caddy if you still have that 940, pm me!

 

[musichal]

My D940 had been sitting unused for a little under a year. I began getting it ready to list on ebay but just to be on the safe side I decided to give it a test run before I declared it perfect. Much to my chagrin, I discovered the tuner display is now not functioning correctly. The tuner preset and scan functions perform normally, the digital display will not reflect changes made to the tuner frequency settings- and remain unchanged. Toggling back and forth between AM/FM many times seem to eventually call up the correct numeric frequency. Also the display will show a decimal point for AM and none for FM at times. Now my question: any suggestions as to if I should get the unit repaired before offering for sale or simply offer AS-IS? Everything else works fine and the unit is mint with original receipt, owner's manual, AM loop antenna, original Proton literature, Proton's "white paper" detailing the DPD amp's performance and test report from Audio (8/86). I'm assuming something is up with the IC programmer chip. My fear is that with the malfunction, the unit will bring next to nothing but it is really such a nice unit, I simply cannot bring myself to give it away for nothing. Any suggestions from somebody who has some degree of technical knowledge as to what may be involved would be tremendously appreciated.

From someone who has a little experience with a soldering iron, but not a lot of technical knowledge: I had almost exactly the same problem with a display on an NAD tuner once, and after opening it up hoping to locate a cold solder joint or something to plug or wiggle to make a contact, I managed to cure the problem by somehow completely losing any display at all.

The tuner still worked, but required a lot of patience to figure out which channel it was on, in order to know which direction to find the desired channel. Made me appreciate how difficult it might be for a blind man to find a channel - don't even think of trying to program one. That was an NAD 4155; it now sits on a shelf in my garage unused as a reminder to me not to exceed my limitations.

I say, "Go for it!"

 

[DualRef]

Back in the early 90's I had a Proton computer monitor. Every three or four months it would quit. Arcing, smoking, buzzing you name it, it did it. The dealer would replace it for me each time only to have the same problems reappear. After about a year of this, I tossed it and bought a NEC monitor.
Here is a short history of Proton..... they've been around awhile.

 

[model1]

I just picked up a Proton 1100 preamp on ebay for $40.

It has a cut power cord, but as soon as I get a chance, I'll replace that and try it out with my Luxman M-300. I saw the posts about them here, otherwise I was not familiar with the company. It looks like new inside, so I am curious to see what it sounds like (or doesn't sound like). The specs posted here looked good on paper, at least! I can always put it back on ebay, if needed....

 

[DCinDC]

That's a good preamp with a nice phono preamp in it. The output relay is unobtanium though and can cause problems.

 

[model1]

I enjoy having different phono options, such as moving coil, that is certainly a plus!
Unobtainium rigormortis could be it's death, then.

 

[DCinDC]

i fixed mine with a different relay, but it was an exercise...

 

[weasel2htm]

I have a Proton All-in-one unit in my basement

Not one of my better videos and it's an older video at that:
http://www.youtube.com/watch?v=H7uZKQ4eGUo

The CD player and some of the buttons need a little diddling sometimes, but everything on it plays perfect!

I've been trying to find stuff on this company, it seems that they are liked, but not well known, If anybody wants some high-res pics of the unit in the video, I get off work early today, and could take it outside and get some good pics of it in good lighting.

This unit was the first I had ever seen of the Proton name, the fact that it still works after being so banged up I think says something, I would like to see more information on Proton.

 

[jmchrislip]

I had two of the Proton 1100 preamps at different times and both had intermittent loss of one channel. I loved the sound but would be cautious about buying another. I primarily use the Kenwood [TRIO] "Audio Purist" C1 preamplifier and find it sounds much like the Proton 1100.