| Bob2 |
Hi guys
I have a Pioneer Gm 120 amp I would like to resurrect. Does anyone have a schematic for this amp. It's atleast 20 yrs old. Deck and speakers where stolen, never replaced them and just stored the amp. Hoping I can now put it to some use.
Thanks
bob2 |
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| planet10 |
| quote: | Originally posted by Bob2
It's atleast 20 yrs old |
At least... vintage 1980 or earlier
dave |
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| Bob2 |
Hi Dave
I was trying not to date myself, but, you are correct. I think I bought it in the late 70's.
bob2 |
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| JOE DIRT® |
| Bob that was a half decent amp in its day along with the component series pioneer had to offer....have you tried firing it up? |
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| Bob2 |
Hi Joe
I did like the sound of the system. I am sure the amp still works,
there was no damage to it, had it hidden under the sit, they never found it. Thats why I hope to be able to use it again. I just not sure how to connect it up.
Bob2 |
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| planet10 |
Bob,
Send Terry @ Sound Hounds <soundhounds -- at -- shaw.ca> an email, he may well have the info you need.
dave |
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| Hi Speed |
Hi Bob2 and all
This is my first post !!
Yes I have a schematic of GM120 but I will try to scan it, let me some time and I advice you. |
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| Bob2 |
Thanks Hi Speed, I patiently await
Bob2 |
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| Hi Speed |
Hi Bob2 :D
I try to upload the Schematic in zip format but the system warning me the following "The file that you have tried to attach is too big. The maximum size is 102400 bytes"
the file is 320kb, is possible you write to my e-mail and I reply you and send you the file. !!! |
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| AcmeRepair |
Hi Bob!
Don't know if you still need it but I have the service manual for your GM-120. I sure could use the owners manual if you have it.
Please let me know.
Thanks,
Steve |
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| gugsi |
Hello
I´m from austria.
I have the amplifer gm120 from pioneer too.
You have anybody a manual for me!?
Can you mail me the manual, please?
gugsi@gmx.net
Do you know, is the amplifer able to bridge 1x120W for a subwoofer?
greetings form austria
gugsi :-) |
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| redhorseaudio |
| quote: | Originally posted by Hi Speed
Hi Bob2 :D
I try to upload the Schematic in zip format but the system warning me the following "The file that you have tried to attach is too big. The maximum size is 102400 bytes"
the file is 320kb, is possible you write to my e-mail and I reply you and send you the file. !!! |
Hello Hi Speed,
I have the amplifer pioneer GM120. Can you mail me the schematic of GM129... please?
on my email: redhorseaudio@yahoo.com |
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| Hi Speed |
Hi all
I have a scaned version of the GM120 sch, I will to upload here is 312kb, this amp can't be bridged, maybe if you make one of the input signal out of phase. |
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| pure |
.
Hi Speed, thank you for posting schematics, here is one GM 120 owner too. The problem is I can't unzip the file because it is corrupted..:bawling: |
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| Hi Speed |
Hi all
Sorry for this,
If anybody need it send me a email to mc_tech@yahoo.com |
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| freakomania |
Hi everyone (from holland)
I have also this pioneer gm-120
it does not switch on
can somebody send the pinouts
to:
mpaymans@gmail.com |
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| mekme |
Hello.
I have an gm120 also.
The problem for me is the inputcable.
How do i wire it?
Does anyone know?
Best regards,
martin |
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| thatsupraguy |
I have the same question. I know it's a vintage amp, which is exactly why I want to use it in my vintage Supra. But I want to cheat a little and use a newer head unit. (In addition to the power wire, ground wire, and speaker outs), The amp originally used an 8-pin plug to attach only to vintage Pioneer head units for its input signal. I went ahead and cut and disected the cord trying to figure out how to connect it to a newer head unit. Inside the outer wire braiding (similar to co-ax), I found 3 wires: a red 18awg single conductor, an orange 18awg single conductor, and a grey multi conductor. The grey multi-conductor contains two smaller wires (red and white) surrounded by wire braiding (again like what you find in cable TV coax).
Anybody know, or even care to take a guess, (or can tell me how to test to find out), which wire does what. |
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| dce |
Hello everyone,
I have experience working on pioneer gm120.
I fix a lot of those 13 yrs. ago. Its a bit difficult to work on those
because it is a double sided board and difficult to remove the solder, if you are not a well experience on removing the solder
on that unit, you might ruin the foil. It is really a nice amp.
Actually, I think I have still four of those in my closet.
If anybody need some help to troubleshoot, maybe I can help,
but I need to refresh my memory because its long time ago.
dce |
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| anatech |
Yup, the protection trace runs on both sides of the board. It's hard to trace.
The input level is 20 dB below the normal level. You may need to pad it. I once made a tester or these and the decks so you could run one without the other. Don't know if I can find it. It's been soooo long.
-Chris |
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| nine76chris |
Any of those GM120's for sale DCE?
-Chris |
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| dce |
chris,
they are not for sale. sorry.
had them for years. sentimental value.
sometimes you can still get them on ebay, but
very seldom and sometimes they are tampered already (not in good shape) I will let you know if somebody I know is selling.
cheers,
dce :) |
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| nine76chris |
Ok, how bout some nice pictures of the inside. I'm trying to fix one that I bought all torn apart, need something to go off of. I got the schematic but the PCB doesn't have component designators, which is making it slow going.
-Chris |
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| anatech |
Yes, I recall that repairing these is slow going until you've done a couple.
-Chris |
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| dce |
chris,
Ok I will take a picture of it as soon as I can.
I'm sorry for the late reply...I am really busy lately
trying to get some things done. :)
dce |
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| Staticjeep |
| how about an picture of the amp, both inside and outside, im just curious to see what it looks like... thanks |
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| dce |
hello,
hopefully tomorrow, I will take a picture
of the inside and outside of GM120.
What is your email add so I can email it.
dce |
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| dce |
hello,
GM120 pictures |
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| alfa147 |
| it is very poor amplifier.I thing forget it. |
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| bahc |
Hello everybody
I'm a "PIONEER enthusiast" and i have fixed a few of those amplifiers.
If you want help, you can describe the problem, and i will try to help you for repair.
First please check the voltage between the blue wire and the ground.
It's a very good device, and it's a great pity of throwing it away.
Sorry for my bad english
friendly wave from France.
Marc
:) |
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| maximus01can |
G'day all,
Found this thread when searching for some info. I have one of these old GM120 gems as well as the equalizer, casette deck, a pair of 6x9's. Had the tweeters, but they got ripped off the dash...this old unit sounded really good in my old chevelle back what seems like a hundred years ago, but I'd like to wire this unit up to my sons head unit. The only thing I'm short on is how to get that wiring harness apart and see what is what. I did find a bit of a schematic on another forum, but they wanted me to buy points or something to download it..........so stupid........anyway, if anyone has any more ifo on this I'd appreciate it.
Cheers,
max |
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| Matschi |
Hi there !
I also got a Pio GM120, but it don't switch on .
Can anyone please send me a scheme or a pinout or something.
Have You got any ideas what i can check? I want to bring it back to life.
PS: Sorry for my bad english
Matschi |
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| bahc |
Hello Matschi
As i say in my post, please check the voltage between the blue wire and the ground, and check also the voltage you give to the amplifier.
I will help you.
Marc
:smash: |
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| bahc |
Just a question i have forgotten, what kind of component you plug to the GM 120 ?
Marc
:confused: |
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| Matschi |
Hi Marc !
Thanks for your help!
As signal source i tested many things, like home cd players or pre outs of my car radio , but i think the problem is that the amp doesn't switches himself on .
as remote I use +12V on the long orange wire . black as GND and red as +Vcc. For audio in there is a cable with two RCA / Chinch plugs.
Have you got a pinout for the Special connector?
Between the blue wire (from near the connector to the metal near the supply) and GND , there are 11-12 V
Greetigs from Germany
Matschi |
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| Matschi |
I forgot ,
How many Ampere takes your GM 120 in standby mode (switched on, no signal, no speakers) |
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| bahc |
In standby mode the amplifier do not need current, because the amplifier can run, only when a another device (Pionner Component),is plugged (to the big connector), he works when a electric consumption is detected.
So if you want to plug the GM-120 to another device (not Pionner Component), it's necessary to make a modification on the card, in this way the amplifier will be switched-on as soon as the power is on.
I will prepare for you a schematic with the broaching of the big connector, and the modification to apply, (only a resistor to add).
Can you give me your direct email, because i can not send you all the informations on the forum.
Good night
Marc
:o |
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| Matschi |
Hi again !
Thank you very much for your work, i didn't know that its neccessary to plug a pioneer component to.
it would be great if you can send me a scheme for the modification and a pinout for the big connector.
Please send it to dare_d@freenet.de
Oh, and can you please say me what the thin orange cable is for ?
Matschi |
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| Turiel |
Hi, I have a GM120 and will try install in my car.
I test the power on with a 1 Kohm resistor between blue and black cables.
Sorry for my english..:smash:
Regards from Argentina.:) |
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| bahc |
How can you test with a 1khoms resistor ??
First check the voltage between the blue wire and the ground with a multimeter, and give me the result.
Important: what do you want to plug to the GM-120 ?
Marc
:confused: |
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| anatech |
Hi Marc,
Sticking a 1K resistor between blue and ground should turn the amplifier on. The 1K draws enough current to trigger the amp on. The most common fault with this circuit are blown traces and shorted e-b on the current sense transistor.
-Chris |
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| zeonrider |
Does , any of you realy have schematic of GM 120, because I wrote 6 ( six ) times to HI SPEED & Hi doesn't send me . Iam asking everybody who have schematic to send me !
linkxp@eunet.yu |
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| anatech |
Hi zeonrider,
I used to have it, sorry. It's at my old shop and unreachable.
I fixed my first ones by tracing out the circuit with a meter. It wasn't fun. I will always remember the experience.
-Chris |
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| zeonrider |
Somebody asked me what wrong with amp. It wery simple.
I can't switch ON. Nothing is burned, everything is OK.For me is wery hard to repair without schematic because I dont see very small objects & I have 47 , I have money but Ican't pay & schematic cost around 20 Euro , this amp is much cheaper .
Thanks to ALL DIY-s |
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| dce |
did you download the one in zip file
by hi speed?? |
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| anatech |
There it is!
-Chris |
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| bahc |
Hello zeonrider
If there is nothing plugged on, it's right.
The amp is not necessarily out of order.
Marc
:att'n: |
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| rossco86 |
Hey all,
Stumbled onto this site through google looking for information on the gm-120 amp. Was delighted to find a schematic for this amp, but very disapointd when the ZIP file was corrupt. Anybody have a copy of it around still??
Ross |
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| maximus01can |
G'day,
Just thought if anyone want's the schematics I have, just email me with your address or post your address and I'll forward them to you. I also have the manual as well as the schematics.
Cheers,
Max |
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| Dj-timoty |
Hello...
I am an owner of an GM120 ...
Can Anyone send me some information about it
want to cable it up in my car :) but have no clue how to do it.. lol :smash:
My current car audio is :
Head unit : Panasonic CQ-C7301N (2006model)
amp1 : JL audio monobloc 200W
amp2 : Xzound "1200W" 5ch (LOL LOL LOL LOL) <--- sucks , i use it on my mid-ranges :clown:
Subwoofer : 2 x 10" JL audio
6x9" : Altec Lancing
etc : BLG 6,5" + tweeters , Rockford fosgate cabels etc |
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| bahc |
OK, but GM-120 is only 2 x 35 W (60W maxi) amplifier ??????
:eek: |
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| Dj-timoty |
yes but i gonne use it on my Altec lancing 6x9 , who has a high working-range to how mutch power they get... :)
sorry for my bad english :smash:
Tommy - Norway... |
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| bahc |
Can you give me your direct email, i have informations (Picture and schématic) for you.
Amicalement
Marc
:) |
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| Dj-timoty |
tommystensland-at-hotmail.com :)
-at- = @ ;)
Thank you :) |
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| bahc |
Hello Dj-timoty
Do you have succeeded to connect your amplifier to you head unit ?
Please let us know.
Marc
:xeye: |
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| Dj-timoty |
| have not tried yet . I will let you know when it`s done :cool: |
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| mrfixall |
| I also need schematic for Pioneer gm-120. email to:imapht@yahoo.com |
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| Perry Babin |
http://www.bcot1.com/gm120/
It's in Flash format. When you open the file, maximize the window. Use the right-click menu to zoom in. The resolution is good once you zoom in. |
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| miikka |
Hey,
I got this old Pioneer GM-120 amp from my friend. If you have schematics or servicemanual for this one, could someone email it to me?
my addy is miikkakallberg@hotmail.com
Thanx |
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| gaarder |
Hello
I have one of this amp`s but I dont know how to connect it to another header...
so could someone please email me the schematics and manuals for the amp?
from andreas |
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| dce |
http://www.bcot1.com/gm120/
this site came from perry babbin
it should be posted there.
gaarder, this amp is connected to a headunit
with din jack type compatible.
like KEX-70, KPX,9000, and so on.
it could also be connected to an equalizer
like CD-9, and CD-5. |
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| mb70rs |
| quote: | Originally posted by anatech
Hi Marc,
Sticking a 1K resistor between blue and ground should turn the amplifier on. The 1K draws enough current to trigger the amp on. The most common fault with this circuit are blown traces and shorted e-b on the current sense transistor.
-Chris |
Hi Chris,
I have been reading the posts on the GM-120 and I would like to thank everyone for their input.
I would like to use my old GM-120 with a non component cd player (i'm looking at possibly the new Pioneer DEH-P3900MP) . I have not been able to get the amp to power up without an original Pioneer component. What you have mentioned above sounds like this might be what is causing the issue. I was looking inside of my amp today and I was wondering if you could help me locate where to connect the 1K resistor to GND (I see at least 3 blue wire locations inside)
Sorry for digging up a really old post and any help would be very much appreciated.
Thanks,
Mike |
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| anatech |
Hi Mike,
Without the original documentation to go by, I don't think I can help you. About 20 years ago (maybe more) I built a breakout box for the GM series amps. I could trigger and run signals to and from headunits and amps. The amp input level is about 20 dB below normal signal levels (go figure - in a car no less!). You will therefore have to attenuate your signals by 20 dB. You need to amplify an old head unit by a similar amount to get useable volume out of them.
A shematic showing the old plug and turn on circuit would tell you how to do this. Watch out because the amp supplied the head unit with power.
-Chris |
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| micutu |
hi every one!
I have a similar problem with a pioneer gm-201, I cannot turn it on, can any one help me.
I don't have any wires on the amplifier, but, on the pcb it say, on the big connector acc + backup illum gnd and of course the out puts, and on the 8 small connector mute, in L, in R, swd b+,unswd B+, illum this is the conector that gives me problems. |
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| bahc |
| Do you have the schematic of this amplifier ? |
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| dce |
hello,
this was from mr. perry babin post.
also i believe i have a copy of this manual,
its just i have to dig in my filing cabinet.
there is a way on how to turn this thing on with a resistor.
its really been a while since the last time i work on
GM-120
http://www.bcot1.com/gm120/
dan |
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| Perry Babin |
| That file is in flash format and greatly compressed. To see it clearly, you'll have to right-click and zoom in on the scanned image. |
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| micutu |
| yes I already saw that, but has I told earlier I have a gm-201 which I need to turn on |
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| dangus |
| I'm pretty sure I have the complete GM120 service manual someplace. Contact me if you're desperate for more info, and I'll look for it. I may also have something for the GM40. |
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| anatech |
Hi dangus,
If you don't mind, I would mind some info if your are going to send it anyway. bhomester at gmail dot com.
Thank you.
-Chris ;) |
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| anatech |
Hi John,
| quote: | | Sorry, but you need login in to view this attachment |
I really don't want yet another accound on another board, but thanks for the link. Can anyone please forward the information?
-Chris ;) |
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| Hi Speed |
this is me in edaboard "mcmc"
sorry but I don't have internet for long time ago, i can't reply all e-mails, I can't upload here because is to big,
but, anybody have any link to upload it ?
sorry again |
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| tsteuerwald |
| quote: | Originally posted by dangus
I'm pretty sure I have the complete GM120 service manual someplace. Contact me if you're desperate for more info, and I'll look for it. I may also have something for the GM40. |
Hi Dangus,
I am also very interested in that. Can you email me please the service manual for the GM120 to my email address h DOT juhnke AT saeuferleber DOT de
Thanks!
Cheers
Timo |
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| Hi Speed |
Hi all
I try to attach another sch of gm 120, it look better, but I can't because is too big (374kb) to upload in this forum, and no accept split archives
if any have a solution tell me, I will try to upload in rapid share
ok it's here
http://rapidshare.com/files/23225761/gm120.rar |
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| Zelk86 |
Hi, I'm a new member!
I have read this discussion and I would to try to fix my gm120 too, but I don't understand well what to do... :(
Someone can help me?
(and sorry for my english!!) |
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| dangus |
| Sorry for not checking this thread until now. I've made a note to look for that manual and scan it. |
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| Zelk86 |
| Oh thanks! I wait!! ;) |
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| bahc |
Hello Zelk86
Can you describe the problem ?
I will try to help you.
Regards
Marc ;) |
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| Zelk86 |
ok:
...I have find a electrical scheme and a short manual for my gm...
and I have read previous post but I don't understand how I can modify my gm120 for use it in a moderm car hifi... I know that someone have do this!!
What I can to do??
please help me |
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| dangus |
I've scanned the manual, but the schematic and overlay pages were each spread over two pages (overlapping). I'd like to combine them back to a single sheet. I don't have access to an 11x17 scanner to do them together.
Can someone suggest software that's good for stitching two scans together? I tried an opensource program that was intended for stitching together panoramic photos. It merged the two scans together OK at the edge, but the overall shape of the schematic ended up distorted. |
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| Perry Babin |
You can do it in the GIMP (Google) but you'll have to do it manually.
Open a new file that's 11x17.
Drag each image into the window. Select the MOVE tool (4-way arrow) and align the images.
Save it as a GIF to retain the detail. Set the pallette to less than 256 colors (toolbar IMAGE >> MODE >> INDEXED - set to less than 256) to reduce the file size. |
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| Zelk86 |
| Thanks for your work! But I have contacted Bahc and I have already modified and mounted the gm120 in car. However dangus send to me the material that you have scanned to androbi.et@libero.it ! thanks! |
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| Zelk86 |
Thanks to dangus and zeonrider!!!
Great work!!! |
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| deng25 |
I already tried to sent you a direct mail. But the Operator gives me allways the same answer. So I try to reach you this way.
I still have an original good Interconnector for your Pioneer Amplifier GM 120 to other Pioneer Components, named Pioneer CD-129. Let me know it if you are interested in.
Dieter Engelhardt |
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| tubewade |
Thanks to all who posted information on this amp. I was given one of these in the early '80s when someone else couldn't figure out how to use it. I modified it to work with any brand of tuner/tape unit and installed it in my car. It was miles ahead of the TA7205AP and TDA2002 or uPC1230 amplifiers that my friends were using at the time. I liked it well enough that I bought another one, built an active crossover and used the two amplifiers in an active setup in my car. This was probably 1985 or 1986, way before this setup was common in cars.
In 1987 the first amp dropped one channel so I had to repair it with no schematic or manuals and I can tell you first hand that these are not fun to work on. Tracing the circuit is difficult at best. They are, however, good enough amplifiers that I would still fix and use one today if I had need of a decent amplifier for automotive use.
When I measured the output of these amplifiers years ago the maximum output before clipping was 42 watts per channel, not 60. So I've always considered these to be 25 wpc amplifiers. That's more than adequate for music reproduction, unless you think it's necessary to try to achieve more than 110 dB in a car.
Best regards.
Wade |
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| amp-guy |
I used to do warranty repair on pioneer back when the gm120 were new ( guess that kind of dates me).
I remember that they had eyelets in the pcb which are a bad thing in the automotive environment of drastic temp changes.
we solved the cracked solder joints that plagued this unit by
first removing the solder then run a small bare wire thru the eyelet and solder it directly to the foil( resolder the eyelet too )
this was the problem in most cases and simply resoldering
is a very temporary fix ,when we used this method the problem never reoccured.
I hope this helps someone |
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| cdgsco |
Hello I am new to this community. My name is Carlos Daniel Garcia Savino, I am Venezuelan birth, and now live in the city of Cabudare, Lara State.
I have a Component Car Stere High Power Main Amplifier PIONEER GM-120 100% operating with its full installation kit, with its original box in good condition.
Really that has great sentimental value to me, but since there is at this site a lot of people interested in this product, and because I need extra money, I decided to sell it.
I have no idea how much to ask, so I listen to offers, which can send my direction email: cdgsco@hotmail.com.
PD Excuse me very badly written English but I hope that at least can understand the message.
Greetings |
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| mitoko |
| quote: | Originally posted by dangus
I'm pretty sure I have the complete GM120 service manual someplace. Contact me if you're desperate for more info, and I'll look for it. I may also have something for the GM40. |
Hello dangus,
If you have schematics or servicemanual for GM-40, could you email it to me?
mitoko@geobiz.net
Thanks in advance.
Regards. |
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| bongraider |
im digging this up coz i got a complete pioneer component setup and i wanna change the kpx-9000 installed with a newer hu. i'm still gonna use the CD-5 equalizer coz i like it.
thanks to all those who supplied info. though i havent been able to see the rapidshare scans, i hope all your help leads me somewhere. thanks |
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| Damqik |
| This help some people. |
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| dangus |
| quote: | Originally posted by mitoko
If you have schematics or servicemanual for GM-40, could you email it to me? |
Sorry, I haven't come across anything for the GM-40. So, I may be mistaken about having any info on that model. If something turns up, I'll post it here.
It wouldn't be hard to trace a schematic, though. Take a picture of the solder side, reverse it, play with the brightness/gamma/contrast to make the traces more visible, then draw in the components. Highlight/trace power and ground with colored pens, then create a schematic. If the board is very dense, desoldering components will help. Make sure the identity and orientation are recorded accurately, of course. Digital cameras or a flatbed scanner are a great help. |
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