Author Topic: Adcom 5800 bias and DC balance repair help in Pittsburgh area?  (Read 8154 times)

Offline strlok

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Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« on: November 08, 2020, 10:58:12 PM »
Hey folks,

Found this forum from a google search trying to find vintage audio equipment repair in the Pittsburgh PA area.

I received a mint condition Adcom 5800 amp that I believe the bias and DC balance are off. The high end sounds harsh.

Supposedly the four cheap potentiometers, two for each channel, may have changed their position while enroute to me via shipment and need readjusted.

I was wondering if anyone here knows anyone in the Pittsburgh area that could help re-bias and adjust the DC balance in my Adcom? It also seems like swapping out the capacitors (this is an old 1994 amp) might be also beneficial but not sure.

Thanks,
Rob

Offline Sir Thrift-a-Lot

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #1 on: November 08, 2020, 11:07:33 PM »
What part of town are you in?   Do you have a manual?

Offline strlok

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #2 on: November 09, 2020, 01:47:19 AM »
Hi, I live in the Castle Shannon area, South Hills.

I do have the 5800 Service Manual which has the schematics:

https://www.manualslib.com/manual/972393/Adcom-Gfa-5800.html#manual

Offline strlok

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #3 on: November 09, 2020, 01:49:36 AM »
Sorry doesn't look like I can edit my previous post.

But here is an owner's manual as well:

https://www.manualslib.com/manual/206141/Adcom-Gfa-5800.html

Offline Vpgh

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #4 on: November 09, 2020, 09:48:12 PM »
Sorry doesn't look like I can edit my previous post.

But here is an owner's manual as well:

https://www.manualslib.com/manual/206141/Adcom-Gfa-5800.html
You can call to Galaxie Electronics @ Murray/Sq. Hills.

Offline strlok

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #5 on: November 09, 2020, 09:57:42 PM »
You can call to Galaxie Electronics @ Murray/Sq. Hills.

Thanks for the recommendation. Can you tell me more about Galaxie Electronics? Are they experts at repairing old Adcoms?

Offline strlok

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #6 on: November 09, 2020, 10:54:36 PM »
Ooof I'm dumb. Looking through your post history looks like you run Galaxie. 8)

Sorry about that. I will give you a call ASAP (looks like Thursday is when you open back up shop at 10am).

Thank you for responding.

Offline Sir Thrift-a-Lot

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #7 on: November 09, 2020, 11:58:49 PM »
Ooof I'm dumb. Looking through your post history looks like you run Galaxie. 8)


You're not as dumb as me.   I didn't realize that.

Offline MacGeek

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #8 on: November 10, 2020, 08:06:09 AM »
I am not sure about Adcom, but Galaxy is good at vintage hi-fi, IMO.  My experience suggests they are fair and stand behind their work.  I last talked to Vince a couple of months ago and hours of operation have been restricted, due to COVID.  I suggest talking to them before taking your gear for service.

By the way, Vince told me he does not like working on surface soldered circuitry or subwoofers.
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Offline scorpio333

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #9 on: November 10, 2020, 09:35:00 AM »
Ooof I'm dumb. Looking through your post history looks like you run Galaxie. 8)

Sorry about that. I will give you a call ASAP (looks like Thursday is when you open back up shop at 10am).

Thank you for responding.

I'm fairly certain vpgh and Vince from Galaxie are NOT related in any way...or did I miss something???

Vince from Galaxie is more old school, he doesn't like the newer integrated chip "black face crap". Regardless, shoot him a call and be patient, last I heard he was knee deep with no end in sight.

Offline strlok

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #10 on: November 10, 2020, 09:11:08 PM »
I'm fairly certain vpgh and Vince from Galaxie are NOT related in any way...or did I miss something???

I looked through his post history and his name is Vince, so I assumed they are the same person?

Quote
he doesn't like the newer integrated chip "black face crap".
Do you have an example of what you mean by this? Sorry I'm sorta new to audio electronics in general and wonder what you mean.

Thanks again guys for your help!

Offline EmperorNorton

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #11 on: November 11, 2020, 07:02:59 PM »
I will chime in here. 

There are absolutely two Vinces.  One  is the moderator here and the other runs Galaxie Electronics.   
"black faced crap" is a somewhat pejorative term used to describe the styling of much consumer grade audio gear manufactured in the 80s and beyond.   
It was the design syle that replaced the classic 60'/70's silver faced/ wood cabinets of the Pioneer/ Yamaha/Marantz equipment, to give a few examples. 

Welcome aboard, by the way!!

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Offline Vpgh

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #12 on: November 11, 2020, 10:56:26 PM »
I will chime in here. 

There are absolutely two Vinces.  One  is the moderator here and the other runs Galaxie Electronics.   
"black faced crap" is a somewhat pejorative term used to describe the styling of much consumer grade audio gear manufactured in the 80s and beyond.   
It was the design syle that replaced the classic 60'/70's silver faced/ wood cabinets of the Pioneer/ Yamaha/Marantz equipment, to give a few examples. 

Welcome aboard, by the way!!

The Emp
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Offline Sir Thrift-a-Lot

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #13 on: November 12, 2020, 12:24:14 AM »
integrated chip "black face crap".

I've always heard it as black plastic crap or simply BPC.

Offline scorpio333

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Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
« Reply #14 on: November 12, 2020, 08:36:04 AM »
integrated chip "black face crap".

I've always heard it as black plastic crap or simply BPC.

I believe you are correct...black face is a whole different realm we don't need to talk about.