Peavey 6505+112 - input without sound

This forum is for talking about all kinds of Peavey guitar amplifiers.
Post Reply
fxcm8
New Member
Posts: 6
Joined: Fri Sep 22, 2017 4:36 am

Peavey 6505+112 - input without sound

Post by fxcm8 » Fri Sep 22, 2017 5:07 am

Hi guys,
when I plug a guitar jack into my 6505+112 combo INPUT, there is no sound, no noise, nothing from there... But using FX RETURN socket on backside, the combo sound normaly, of course without possibility of changing volume and other sound parameters, only from my effect I can modify my sound, but in any case, from my effect (GT-100) it plays normally.
When I bought it it worked normally, since I use it only with my GT-100 connected by 4 cables, but now I tried to plug it to the INPUT socket but my INPUT seems to be dead...
So I don´t know if there is a problem with the pre-amp or if there is some small "stupid" problem or a serious one. Maybe the preamp tubes are broken, should I change them ?
Do somebody have some opinion, suggestions ? Thanks

KTB
Member
Posts: 2241
Joined: Mon Oct 06, 2008 7:53 pm

Re: Peavey 6505+112 - input without sound

Post by KTB » Fri Sep 22, 2017 6:12 am

Try the preamp out to another amp and if it works the preamp tubes are good. Are they lighting ? Obviously the PI tube is working because it's part of the output section. Input jack could be bad.

fxcm8
New Member
Posts: 6
Joined: Fri Sep 22, 2017 4:36 am

Re: Peavey 6505+112 - input without sound

Post by fxcm8 » Fri Sep 22, 2017 1:45 pm

I checked it...I connected the preamp output to another amp and there is no sound from the preamp. Also the preamp tubes it seems no lighting from them, only two power tubes Works they are red, but the preamp tubes are without signs of life. I can´t campare how it should light. So maybe it seems pre amp is dead, hope that tubes replacing will solve it.
Input jack is good, I tried several different cables there.
Question is if such failure is normal, when all 5 preamp tubes stop working at the same time or it may be caused by some unproper activity or connecting to effects, or guitar, ... or switching off the main power switch, without switching the standby switch first ?

KTB
Member
Posts: 2241
Joined: Mon Oct 06, 2008 7:53 pm

Re: Peavey 6505+112 - input without sound

Post by KTB » Fri Sep 22, 2017 6:13 pm

Can almost guarantee the preamp tubes are good. 5 preamp tubes aren't going to go out at the same time. Turn the lights out and check them and make sure there is no lights as they sometimes don't glow very bright especially spiral filaments. If they aren't lighting it's probably a connection or cold solder joint but that explains why it's quiet.

User avatar
Pappy B
Member
Posts: 767
Joined: Sun Jan 31, 2016 2:30 pm

Re: Peavey 6505+112 - input without sound

Post by Pappy B » Fri Sep 22, 2017 8:39 pm

Try putting a cable from preamp- out to Power - in. May be a jack problem.
The more I learn the more I realize how much I don't know.

fxcm8
New Member
Posts: 6
Joined: Fri Sep 22, 2017 4:36 am

Re: Peavey 6505+112 - input without sound

Post by fxcm8 » Sat Sep 23, 2017 10:15 am

KTB - yes maybe cold solder joint, also maybe transformer failure but I don´t have the wiring schematic diagran with voltage adn other values to check outgoing voltage there... So, it require more deep checking all of inside parts.
Do somebody have a wiring diagram with values ? I found something, but only a EVH-5150 combo, they say that it sholud be the same as 6505+112, I am not sure for 100% abt it

fxcm8
New Member
Posts: 6
Joined: Fri Sep 22, 2017 4:36 am

Re: Peavey 6505+112 - input without sound

Post by fxcm8 » Sat Sep 23, 2017 10:24 am

Pappy B - and what do we achieve? Once the preamp is dead, there is no outgoing signal grom preamp-out. It probably is some problem in front of the tubes, so only disassemble and examine

KTB
Member
Posts: 2241
Joined: Mon Oct 06, 2008 7:53 pm

Re: Peavey 6505+112 - input without sound

Post by KTB » Sat Sep 23, 2017 12:04 pm

You can email Peavey customer service and get a schematic.

User avatar
Pappy B
Member
Posts: 767
Joined: Sun Jan 31, 2016 2:30 pm

Re: Peavey 6505+112 - input without sound

Post by Pappy B » Sat Sep 23, 2017 10:49 pm

Well, I had missed where you have already gone from your "pre" out to another power in. I was just suggesting a quick check to make sure you have (or don't have) signal flow from the pre amp to power amp.
The more I learn the more I realize how much I don't know.

fxcm8
New Member
Posts: 6
Joined: Fri Sep 22, 2017 4:36 am

Re: Peavey 6505+112 - input without sound

Post by fxcm8 » Sun Sep 24, 2017 11:44 am

Sure...thanks for suggestions...now is time to disassemble it, this will take me "couple" das, when I find some time for it. I will inform you when I´ll solve it, thanks you guys for now.
Interesting that product of this category, quality and price is able to have such trouble...

fxcm8
New Member
Posts: 6
Joined: Fri Sep 22, 2017 4:36 am

Re: Peavey 6505+112 - input without sound

Post by fxcm8 » Mon Nov 20, 2017 2:14 pm

Hi guys,
couple of weeks passed and I successfully solved my problem. Before I started to disassembly my amp, I deeply study what potentialy and I consult with my friend abt it.
Finally...there was the rectifier circuit broken (diods was short circuid) which is responsible for warming up of V1 - V4 preamp tubes (...see schematic diarham). After replacing them (four diods) and also 5 pcs of capacitors, my amp is working properly and in full power :))))))

It is very shortly how I solved my problem but if somebody wants more deep description of this procedure, then I can describe it by all details. It is serious technical matter and you need correctly read electric schematic diagrams and be skilled with electro devices repairing.
Included photos you can see what was the problem.

Costs for repair aprox. 4 EUR (four euro) ...for comparison, in brand service centre it should be much more :)Image
Attachments
03.jpg
03.jpg (33.87 KiB) Viewed 4049 times
02.jpg
02.jpg (27.15 KiB) Viewed 4049 times
01.jpg
01.jpg (32.75 KiB) Viewed 4049 times

Post Reply