Pioneer Pro Amp With No Model Number, Anyone Ever See One Of

One wierd thing about this one also is that from the voltage readings on the good (in fact both) channels, it uses bipolars but with the base or emitter in the middle. You can see the construction there, they mirrored it but flipped one side upside down. However input and all that are on one side. Why the hell didn't they just mirror it the other way ?

Anyway, I doubt it needs outputs from the readings, but it seems the outputs have the base (or maybe the emitter) in the middle, not the collector. And they are all the same polarity. I can't see the numbers and I am not taking that part of it apart unless necessary. But on one side they got like -100V on two pins and 0 on the other. On the other ones they got +100V on one pin but 0 on the other two. The difference is that the other is on the end instead of the middle.

Anyway, here are some pictures (higher res available on request) :

https://dl.dropboxusercontent.com/u/29948706/piox/pi01.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi02.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi03.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi04.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi05.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi06.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi07.jpg

It may be a little hard to see in those pictures but it is a two sided board which makes any reverse engineeering alot harder. If I could just find a print it would help.

I got no output on the right channel, or B or whatever. It is not in protection. The readings look the same as the other channel.

Any idea what it is ? Any help is appreciated. If not I gotta tear into it blind because you really can't get to much. Anything, even the model number might help. I doubt any idiot ripped the numbers off because it was hot because the serial number is still there.

 

[Phil Allison]

jurb...@gmail.com wrote:

One wierd thing about this one also is that from the voltage readings on the good (in fact both) channels, it uses bipolars but with the base or emitter in the middle. You can see the construction there, they mirrored it but flipped one side upside down. However input and all that are on one side. Why the hell didn't they just mirror it the other way ?

Anyway, I doubt it needs outputs from the readings, but it seems the outputs have the base (or maybe the emitter) in the middle, not the collector. And they are all the same polarity. I can't see the numbers and I am not taking that part of it apart unless necessary. But on one side they got like -100V on two pins and 0 on the other. On the other ones they got +100V on one pin but 0 on the other two. The difference is that the other is on the end instead of the middle.

Anyway, here are some pictures (higher res available on request) :

https://dl.dropboxusercontent.com/u/29948706/piox/pi01.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi02.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi03.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi04.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi05.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi06.jpg

https://dl.dropboxusercontent.com/u/29948706/piox/pi07.jpg

It may be a little hard to see in those pictures but it is a two sided board which makes any reverse engineeering alot harder. If I could just find a print it would help.

I got no output on the right channel, or B or whatever. It is not in protection. The readings look the same as the other channel.

Any idea what it is ? Any help is appreciated. If not I gotta tear into it blind because you really can't get to much. Anything, even the model number might help. I doubt any idiot ripped the numbers off because it was hot because the serial number is still there.

** That is a USA made amplifier - not Pioneer.

FYI: Asian electronic gear has metric thread bolts and I but that POS has Yankee ones.

If the middle pin on a large flyt pak is not a collector, then the devices are lateral Mosfets.


.... Phil

 

[Jeff Liebermann]

On Fri, 10 Apr 2015 19:29:31 -0700 (PDT), jurb6006@gmail.com wrote:

>Any idea what it is ? Any help is appreciated. If not I gotta tear into it blind because you really can't get to much. Anything, even the model number might help. I doubt any idiot ripped the numbers off because it was hot because the serial number is still there.

Well, the sticker says that it's made by Pioneer:
<https://dl.dropboxusercontent.com/u/29948706/piox/pi03.jpg>
but is sure doesn't look like anything made by Pioneer. It also says
made in 2004 but looks older. I also don't recall anything by Pioneer
with a fan (although I may have missed something).

I did some image searching, but couldn't find anything by Pioneer that
looked even close:
<https://www.google.com/search?tbm=isch&q=pioneer+amplifier>

My guess(tm) is that it's either a counterfeit, or someone just stuck
the Pioneer name on some other device in order to enhance its resale
value.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

"<https://www.google.com/search?tbm=isch&q=pioneer+amplifier

My guess(tm) is that it's either a counterfeit, or someone just stuck
the Pioneer name on some other device in order to enhance its resale
value. "

I had serious doubts about it being a Pioneer and I appreciate the confirmation. As far as enhancing its value, it has probably more power than most Pioneers. (I just looked and now they are into class D3 at alot more power, but this thing is not new)

I doubt a company would just stick the nameplates on there, it may have been a seller. I will have to query this guy to find out where he got it but I wouldn't count on that going too far. It was in his stash. He owns a bar and his soundguy walked off and took his toys so this dude is hooking up his own toys. He already has two 1,300 watt QSCs which do sound damn good. I hooked them up and phased the speakers.

But now he has this other amp and more speakers because the hairs in the kids' cochleas have been shaved off a bit. So they need more. Actually they are into bass bigtime and bass is not so bad for the ears.

But anyway, the thing doesn't seem to have any shorted outputs, it is not even in protection.

I might just have to do it the old fashioned way. Problemm is, I am not breaking the seal between those heatsinks and transistors.

Hm, on a side note, I get involved with the hifi crowd from time to time and I found out that some of them in restoring an old piece, actually take the outputs out and clean it all down and put new virdshit (heatsink cmpound) on them. I think this is crazy. It is settled in real nice. the thermal contact is probably the best it'l ever be and better then it'll ever need to be. What's more if you have mica insulators and stress them wrong they delineate. And I bet they do not check for that. I have mentioned it but got no answers back. I guess you could do that if you want it to look nice, but use new insulators then if you want to have a boat in your livingroom. (boat = hole in water to throw money in)

And I bet they spread it too, instad of putting it evenly at the main force to squeeze it out so there are no air pockets. I told a coworker that 1,000 times and he wouldn't listen. I tried and tried, it makes sense dude, WTF is wrong with you ? Nothing. Ignorance and I bet willful. My old source of this bad information is better than what you say about it that actually makes sense - even though my credentials are better.

Fucking people amaze me. Gotta watch Dr. Hoo. Or wait, not Dr., Inspector or something. It is an ep of Get Smart, which is one of the best of all time BTW. I got a bunch of them. At least after watching them I might be able to put a little insanity into the insanity and enjoy it a bit.

Sorry for the rant. But then, it's Friday.

 

"** That is a USA made amplifier - not Pioneer.

FYI: Asian electronic gear has metric thread bolts and I but that POS has >Yankee ones. "

How could you tell that from the picures ? those aren't even the hi res ones. (not that they're all that good)

>"If the middle pin on a large flyt pak is not a collector, then the devices are >lateral Mosfets."

Never heard of them befroe but oww tht I had a look around the net I se that possible. they said the bias rquirements are similar to bipolar, I assume that means voltage ? I mean, if you have to drive it with current then youo are back where you started. Regardless I did nmeasure about the same voltage on two adjacent pins and a far awy voltage on the other end in all cases. I found the coil whee it comes out and it has no offsaet. The relays are separate fro each channels and I hear them both click in. There is no heavy drain. ust a surge when it comes on. It is pretty hard for it to be anythoing but someting in the signal path rather than the power amps themselves.

I might just have to figure it out myself. But now I am even more adamant about not breaking the seals on those outputs. If I have to pull that channel I will get them but other than that fuck it. The other channel I am leaving alone of course.

I am almost intereted in seeng the actual curves n shit on these lateral FETs. I doubt I'll ever use one purposely in a circuit, but it is nice to know. Like when you read a Tektronix manual and it explains all about tunnel diodes and unijunction transistors. Actually worht the read but, once.

 

[John-Del]

On Saturday, April 11, 2015 at 1:40:56 AM UTC-4, Jeff Liebermann wrote:

I also don't recall anything by Pioneer

with a fan (although I may have missed something).

I guess you missed the joy of the low end Pioneer receivers that had what we call the "music to smoke converter" module. It was a Borg type cube that had all the outputs plus the two driver boards stuffed into a chimney with an exhaust fan that would blow the smoke from the inevitable failure quickly out the back.

http://s753.photobucket.com/user/ronrap2009/media/Receivers-01/Pioneer-M-790-Pwr-Amp-003.jpg.html

 

This unit looks to me like an older Crest amp. They usually have markings on the front, but this one may have either worn off or been removed. Crest systems don't usually have the name on the back either.

The Pioneer name on the back looks like someone added it on.

Dan

 

[Mark Zacharias]

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:gubhiap50n52ujm0ud0vs3trj7t0onth5j@4ax.com...

On Fri, 10 Apr 2015 19:29:31 -0700 (PDT), jurb6006@gmail.com wrote:

Any idea what it is ? Any help is appreciated. If not I gotta tear into it
blind because you really can't get to much. Anything, even the model
number might help. I doubt any idiot ripped the numbers off because it was
hot because the serial number is still there.

Well, the sticker says that it's made by Pioneer:
https://dl.dropboxusercontent.com/u/29948706/piox/pi03.jpg
but is sure doesn't look like anything made by Pioneer. It also says
made in 2004 but looks older. I also don't recall anything by Pioneer
with a fan (although I may have missed something).

I did some image searching, but couldn't find anything by Pioneer that
looked even close:
https://www.google.com/search?tbm=isch&q=pioneer+amplifier

My guess(tm) is that it's either a counterfeit, or someone just stuck
the Pioneer name on some other device in order to enhance its resale
value.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Looks like a legit serial number sticker but I need more pics of the unit
itself.

Inside pics would help too.

Mark Z.

 

jurb6006@gmail.com wrote:

I got no output on the right channel, or B or whatever. It is not in
protection. The readings look the same as the other channel.

Disclaimer: I don't do this for a living.

I would look at those normal/bridging and stereo/parallel-mono switches,
as well as the level pots for the inputs. If there is an op-amp (to
bring a low input up) or maybe a resistor divider (to bring a high input
down) on that input board, check that too. A problem on the input board
might result in nothing getting to the power stages.

Matt Roberds

 

[Phil Allison]

jurb...@gmail.com wrote:

"** That is a USA made amplifier - not Pioneer.

FYI: Asian electronic gear has metric thread bolts and I but that POS has >Yankee ones. "

How could you tell that from the picures ?

** ROTFL !!

I can tell it's a USA made from the pics - lotsa clues that you see only in US made amps.

CONFIRMATION can be had by looking at the threads on the bolts, US threads = US made.


.... Phil

 

[Ron D.]

I serviced high-power amps part-time and You do have to understand bridging. Judging from the "DUST", those switches likely need a cleaning.

With no input and no load measure the DC voltage from ground to + spk and - spk and +spk to ground and -spk to ground L&R in bridge and non-bridge mode.

Particularly you get exactly zero between spk- and spk+ in normal mode, I'd look at the output relay. You should at least see a few mv unless the amp is capacitive coupled.

You have DIN and phone plug inputs so concentrate on the phone plugs.

Relays could exist in the input circuit as well. Without a minimum current or
the right relays, the contacts could be oxidized.

One way to bridge is to invert one signal and to take the output from the + spk terminals w/o using ground.

So what I am suggesting is oxidation of relay contacts on the input or output or something between the ears (user error).

 

>"I guess you missed the joy of the low end Pioneer receivers that had what we >call the "music to smoke converter" module. It was a Borg type cube"

Oh no, I just didn't do audio at th time except for a few high end us-nius came in. I was doing rear projection mostly, where the money was. But I saw them. they gave up on fixing them and were ordering them somnewehere and dropping them in. the parts guy at that place was FANTASTIC. I would say "See if you can get htis, if not I'll work on it sone more". He would have in two days. I have no idea how he does it. He is doing oit for their shop up here and oin FLorida where they are about to semi retire. they already have a shop and once the shop up here is sold he goes down ther and works with his partner down there and thety forget about all this snow n shit. At least that's the plane. Problem is the shop is down to fifty grand and still not selling. they probably shouldv'e sold out about 15 years ago back ewhen I workded for them.

The7 fucked up alot of audio. They are simply NOT an audio shop. they could be wit me but I was no longer willing to work full time, and thenm part timee, and then traded jobs with a guy who lived nearer there and we both saved 20 miles on our commute. And it worked out I guess. None of these Tv places really evr wantd to do audio.

But I wish I could use their parts guy. Today it wouldn't matter as much for a lot of reasons, but his ability to gt parts really made the difference and we watched tho competition go under again and again.

but yes, I am aware of Pioneer's back eye which send them to the bottom end.. you know at one time they buillt what is known as the SX-1980. OPne of the best receivers ever. and now I wouldn't hit a dog in the ass with the best of their best today. Oh yeah, I know it is not sold at Walmart, but if they'll put that name on that, they'll put it on anything. Fukum, they are dead. Stick a fork in them, they are done.

 

>"The Pioneer name on the back looks like someone added it on. "

I had a closer look at that. What a lame ass attempt.

 

>"Inside pics would help too. "

I got what I could. I have put it down for reasons I will explain in another post very soon tonight. If I HAVE to fix it I will be back, with a $150 to $250 estimate approved. the amp might not be worth that in this market so I doubt that is happening.

 

"I would look at those normal/bridging and stereo/parallel-mono switches,
as well as the level pots for the inputs."

I have been at this a whioe. Yes I checked and the input is getting all the way to the amp board itself, which contains all pretection circuitry. I would have switched amp boards except for what I found which is coming in a "supra" post. (not a toppost but closer to it)

 

>"I can tell it's a USA made from the pics - lotsa clues that you see only in US >made amps. "

OK so it was just the looks of the thing. I guess I agree but I am experienced on US, Japanese and Chines/Korean/Viet/Malasian stuff. I know there is alot else out there.

 

"Relays could exist in the input circuit as well. Without a minimum current or
the right relays, the contacts could be oxidized. "

Understood but they don't. I will be back with the results in a few minutes once I get through all the individual issues everyone has brought up.

 

I have gotten into the thing more. I have tested that the input is making it to the board so the mode switches are eliminated. I got good suppies it loks like and both relays are kicking in. there is no offset to speak of.

The defective channel is the one with the components on top. Limited in test points at that point I removed it for dry testing. I found one of the relat contacts had gone bad to the board. It was well corroded and not making connection, I mean it was so obvious even my blind ass could see it.

So I add solder, then wick, then scrape both the terminal and the relay pin thiniking that I might just get lucky. Then I decide just for the hell of it to test the outputs.

We have determined that these are some bastard type of transistors invented on Mars or some shit because the drian/collector is not in the middle. They are som esort of MOSFET. I did not read the channel that works, but after resoldering the one that didn't I checked the resistance between the source and gate of them and one bankk read about 100 ohms or so both directions and the other reads alot less. I forget, maybe 15 ohms or something like that. I thought that unusual but them here is a device with which I am not familiar so maybe that is the way it has to be a quais comp. I resally have very little ideaa of the characteristics of these divcies so how would I know ?

Anyway, I hook it all back up wiht the relay connection fixed and I got hte same thing. there is still no offest but then you got a shorted in leg. Input shorted, not the kind of shorted that causes the fuse to blow.

I thing the connection started going bad and kept on arcing at high pwoier and somehow with that all fucked up load took out the junction(s) in OPNE of the output devoces. Once one is shorted, none of them work, that's the fakt jack. So it can't drive, trying to dfoix the DC offest results in it shuitting down the bias, and that's that.

Oh, and there are no source (emitter) resistors in there.

So I put out an open ended estimate of $150 IF we get extremely lucky and can find identical devices and replace only five of them. there are ten per channel. you CNA get awat with replacing only five because the thing never shorted out. I am figuring ten bucks apiece and just to replace them I want a hundred bucks. This shit is not all that easy and I have no idea if I have to deal with insulators or if they are all "P". Even the soldering is going to be a PITA because it looks like Pbf. And of course it is at least two sided.

And now we come to the customer history. Remeber I mentioned where I work, that some of them don't seem to be aware of the difference between levels ? they brought me a box, an effects box. The complaint was it is noisy. When changing modes and all that. I had to tell EACH AND EVERY FUCKING ONE OF THEM the device is NOT a guitar pedal, you cannot pkug a guitar into it abnd then to the amp, it has to go into a effecs loop. I proved it an d all that shit. And these are the peole who blew out two amps by somehow connectong two amps, one bridged and one not, to the same speaker ! Not only blew out both amps, the bridged one blew ALL the outpiuts, 16 of them, and the other blew only the relay mainly because it is designed to short out the outoupt when it opens from the amp output. this is to prevent arcing over of the contacts which would cause an insidiuos problem, especially for idiots like this. Fucking don't know what line level is ? Keep them away from my stereo. I don't want them anywhere near my Soundesign ! (I alnost shouldn't capitalise that huh)

And this ain't the first time. There was another effects machine that I didn't cathc this on. told then there was nothing wrong with it. Saw soem crazy mod in there and blew it off. the complain t was noise. If I had known they were that fucikng ignorant, I could have told then it works fine and that was done by the factory.

Come on. The clock from one chip was fed to another. Nobody really does that in the field. That is a design error. That was never a fix and I didn't realize the engineering was all that sloppy in this business yet. Now I know.. Live and learn.

I have learned. Now I can see alot of things. I have to totally take over the service but I am not doing it at this salary, and I am not doing it on commision. Maybe later, but not at the current state of afairs. We can stay how we are, I am theonly one on the area with a chance in hell of fixing it, but the opportunity is there.

?They are not bad people, just ignorant of some things, well more than some whe it comes to electronics. I even wrote them a page but will not release it yet, even though I am hosting it. I'll email you it but with all Iv'e said now it would be bad publicity. I don't want that. I want to fix the place, not hurt it. All I need is another job where I take home $40,000 tax free. that's al I want. I don't need your healthcare and you ain't getting my SSN. I'll invoice you. Taxman is scared of me these days. I'll take care of that.

But to be autonomous ? Inside another business ? They already offered me that, keys and all. I have been offered that many times and always turned it down. he ois trying to sell part of his retial space to me and I sdo not see tha value, especuially what they did at that bar. And that bar is MY customer in a way. They might buy shit from the store but I thinkk by now they are not taking any equipment there. The boss keeps teling me that I would do better to buiold businees at his business because people are more willing to takwe htings to a shop than a basement.

Well that bar's amps are coming to a basement. Mine.

thing is, I got options to consider, there is a need. The competition has too long a lead time, iike three weeks to lok at something and give an estimate.

If I can do the work I got this buisiness by the balls. What's more I think I have a backer. Not big money, but enough. there is a whole lot of shit I don't know, but like Dick Cheney said (and oit was fucking stupid) about we know things, we done;t know things, we now thigns we don't know and we don;t know things we don't know. As fucked up as that is, it is about right.

The only thing that keeps me from taking the plunge or committing to that company is the shit I do not know. The company, I don't know those people. I could lose thousands worht of tools in a heartbeat. Not thsat that they would steal them, they might have a foreclosure n shit. I have no idea. Even if they HAVE a D & B rating it means nothing when it comes to shit like that.

I cna't tell them to buy evrything them I am autonomous, that ain't right. And as far as me bringing my good shit in there, well for one it is not all that good. but I am not igving up my home shop by any stretch of the imagination and I ain't geting into any on-competition clauses.

Not sure what to do. An now, in this amp with the relay contact burned and an output effectively leaky B-E or G-S, indictuance did it. what that means is this ap was already fuicking up and they weither couldn't hear it or duecided to let it keep running. Eventually enough inductive kick for that caused the worng polarity spike at the wrong time and caused leakage. Inductive spikes are always the worg polarity. So the relay connection to the board arcs over and that is that.

Enough, this is driving me crazer. I ill figure out what to do. I do appreciate advice. On the amp or the people. Should I just insist on worjking at home wiht my wn policies ? I mean, htese people take in shit saying "call if over $15". No MF. you bring it in you are signing up for fifty bucks with no estimate and you will be lucky to gt it. Or you can go down the street to find out oin a MONTH that they are charging you ten times that much.

Yeah, I git some work to do and it ain't all at the bench.

But how would they know ? I cnba't be pissed off becaus they necer met the likes of me before. when I went to LNB, they said "We never knew what to expect". Meaning that I had got so much domne, nobody even fixed half as much.. After a couple of months they found no recalls. I wass King of the hill and soon made more than the bosses. And they had no problem with that. If they had, they knoew I could just walk.

Is this happening again ? Should I really show my ass. As fr as I know I am already better than anyone they ever met. Is history repeating itself ?

 

[Phil Allison]

jurb...@gmail.com wrote:

We have determined that these are some bastard type
of transistors invented on Mars or some shit because
the drian/collector is not in the middle.
They are some sort of MOSFET.

** One like this ?

http://www.donberg.co.uk/pics/b/buz_901p-1.jpg

http://products.semelab-tt.com/pdf/magnatec/BUZ900P.pd


** These are the only audio power devices that need no ballast resistors when run in parallel and normally have the output signal on the middle leg and heatsink tab.



.... Phil

 

By output do you mean the drain or collector terminal ? As opposed to the emitter or source that is. If that is the case it is on the end on these.

Your link to the PDF on that was no good from here. I found another one though at

http://products.semelab-tt.com/pdf/magnatec/BUZ900P.pdf

which indicates the drain at pin three

I assume you fucked up on the typoing and forgot the word "not". I can't bitch, I am way worse.

Anyhow, upon further investigation I find the relay has a bad connection which has quite obviously arced. I mean QUITE obviously. That is the side that is foill down so I couldn't see it before. There is no bottom access, it is built in a pan.

So I scraped that up and resoldered it and just for the hel of it I thought I would check resistances of the outputs.

On one set of five it reads a hundred and some ohms gate to source. The reading is about fifteen ohms on the other five. At this pont I am almost sure this thing is not going to run. And it doesn't. There is still no offset and the relat kicks in, but of course there is no sound. And again, yes I check it on the board at the output coil and make sure it still has input.

Obviously what happened is this thing was actually running but that conectio started going bad and the inductive kick fed back into the outputs and breached a gate.

I gave him the estomate which was an ammendable ballpark figuring those decices at $10 each and I would be changing at least five of them. And lavor is not the cheapest either because it is a PITA. Well I have seen worse but it is a two sided plated through board so I ain't doing it for twenty bucks.

So he abandoneed it. Said keep it. I don't know what to do with it othr than feed my subwoofer which is the only thing in the house that can handle that much power. It handles 250, this thing, hmm, one channel driven it ...

I only saw the rails on the scope, estimating 95 volts. Says 1,200 watts on the back and has bridged mode, umm, maybe 400 watts ? Or 350 ?

But you said it looks like a cheap amp. Really ? All I know is it didn't fry because of being underbuilt. the solder connection is one thing, but ho old is it ? It doesn't even have a toroid transformer. Twenty years ?

So I dunno, maybe I'll make it pure DC and use it as an instrumentation amp.. I'm sure I can disable the protection and find probably one capacitor to jump out. It does have a DC offset control so it should work.