It is currently Mon Mar 16, 2020 4:08 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 22 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next
Author Message
Post subject: Noise on Twin Amp with reverb on
Posted: Tue Jan 17, 2017 7:47 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 17, 2017 5:52 am
Posts: 31
My Twin Amp is quiet but if I switch on the Reverb it makes a low hum noise even if nothing is connected to it. This noise gets really annoying from 2 on the Reverb knob.

The tubes are new and the amp is correctly biased.

Do you experience the same thing?

Judge for yourselves:
https://youtu.be/7GOSDip8cZs (On/Off test)
https://youtu.be/1Xhl9ridHc8 (little song test)

Thank you.

Cheers


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 2:41 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
I'll clean rca plugs and jacks, amp side and reverb pan side.

Do a test with reverb pan outside the amp

Did you ear the reverb quiet since you have this amp ? Or it was always noisy .


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 3:17 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 17, 2017 5:52 am
Posts: 31
Dear stratele52,

RCA were cleaned. Also jacks.
Outside the amp, it is noisy too.
It was always like this. I bought it one year ago.
Thanks.


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 5:07 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
I did not see what you can do more than try a new reverb tank


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 5:34 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 17, 2017 5:52 am
Posts: 31
I'm on the 2nd reverb tank. First thing I did when bought the amp was change all tubes and the tank. It was biased, also.

:(


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 6:13 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
You may try the wire between amp and tank. I use home stereo quality cable wich work well.

You do all you can, I have no more idea. Few expert here may have some answer.
If TimAudio can be in line...


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 7:26 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 17, 2017 5:52 am
Posts: 31
I've changed the stock RCA cable for one I had at home, used on my first Hi-Fi stereo system. Nothing happened. The noise kept the same.

I'm deeply concerned. I suspect this could be not a mal-function, but a characteristic of some units. One retired tech from USA once told me this:

«I did check our old service records on this model of amp (luckily I still have most of them) and did see two cases of customers bringing in their Twin Amp for excessive reverb noise (warranty coverage). Triage of those amps failed to indicate any defects though there was certainly a low 60 Hz hum evident above about 4 or 5 on the reverb gain. The noise was not objectionable at normal playing volumes. I don't think this made the customers real happy, but that's what we have in our old files. I don't believe this was a problem in all Twin Amps, perhaps an anomaly in some of them.

I have long believed this model amp is over engineered. I am suspicious of the solid state mute circuits and perhaps some shielding issues as well. The case histories of "weird" and really mysterious symptoms I've seen over the years caused by JFETs and other solid state devices used in modern tube amps is extensive. »


I haven't started to dig the leads he gave me because last year I spent a lot of money maintaining and repairing this amp. I need to take a while before I spent more money. However, once I start, I would like to address the problem in the right direction.


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 7:32 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Wildstrat wrote:


I'm deeply concerned. I suspect this could be not a mal-function, but a characteristic of some units. One retired tech from USA once told me this:
.



You may be right, I see lots of bad desing making noise on many new ( and no so new ) Fender amps.


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 7:42 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
stratele52 wrote:
I see lots of bad desing making noise on many new ( and no so new ) Fender amps.


+1

Fender engineers of the post-CBS era have laid dozens of eggs over the years.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 7:49 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Retroverbial wrote:
stratele52 wrote:
I see lots of bad desing making noise on many new ( and no so new ) Fender amps.[/qu
Fender engineers of the post-CBS era have laid dozens of eggs over the years.

Arjay


+1


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 7:56 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 17, 2017 5:52 am
Posts: 31
Is there any chance to get rid of that noise?


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 8:08 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Wildstrat wrote:
Is there any chance to get rid of that noise?


I never work on this amp wich have this reverb noise.
If I had to ,I'll look if I can replace some wire by shielded one on reverb circuit.

Any picture from inside the amp ?


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 9:11 am
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 17, 2017 5:52 am
Posts: 31
No pics.
I'm not able to open the amp. I'm not electronic expert.
I suspect the tech had done it (inspect shields, cables, wires, etc).


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 10:08 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Wildstrat wrote:

I suspect the tech had done it (inspect shields, cables, wires, etc).


Not in my opinion, I talk about mods, tech may see amp are built in Fender specs and no part are burn or need to be replaced.

Doing mods, it is another story, another world.


Top
Profile
Post subject: Re: Noise on Twin Amp with reverb on
Posted: Thu Jan 19, 2017 1:55 pm
Offline
Hobbyist
Hobbyist

Joined: Tue Jan 17, 2017 5:52 am
Posts: 31
I think I didn't understand what you said. Your suggestion was to make a mod on my Twin Amp?


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 22 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: