It is currently Mon Mar 16, 2020 8:28 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 20 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next
Author Message
Post subject: Crackling/Scratching idle noise on Deluxe Reverb Custom '68
Posted: Mon Feb 25, 2019 10:39 am
Offline
Hobbyist
Hobbyist

Joined: Mon Feb 25, 2019 10:12 am
Posts: 1
I have a DRRI custom 68 that is within the warranty period. For the time I have had this amp it has made a terrible scratching / crackling sound, even when both channels are on zero volume. It's very similar to the sound of a dirty pot, but it happens without any signal or interaction with the amp.

Here's a recording: https://www.youtube.com/watch?v=hXNU6BGQchU

It's loud enough to hear from another room. Here's a recording from across the room: https://www.youtube.com/watch?v=2mFmQiBk81E

Both of these recordings were done with my iPhone and no post processing of any kind.

Fender support have seen the first one and tell me this is normal. It makes the amp pretty much unusable though, so I can't believe that this is true.

I've taken the amp to the local official Fender amp repair person, and they got told the same thing by Fender (it is "normal") so they aren't helping.

I'm not sure what my next steps should be. So I thought I would ask here:

Have you experienced this with a Fender amp?
Would you consider this to be normal?

Any other wisdom much appreciated. I'm at wits end. Thanks.


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Sun Mar 03, 2019 3:05 pm
Online
Professional Musician
Professional Musician

Joined: Thu Aug 07, 2014 3:25 pm
Posts: 1022
The surf sizzle you describe is probably from tube noise. So, while it works, its also annoying.
The 68 has reverb featured on both channels. This is a departure from the original deluxe reverb that had only one channel reverb.
This is significant in that the reverb channel needed an extra gain stage to accomplish that. It also meant that the channels ran their signals out of phase.
This is where the shared cathodes of V1b and V2b make some magic. The noise created by the two tube stages is mixed and V4 feeds the differential output. This cancels a large portion of their noise when they mix back together at the input of V6.
The 68 is not out of phase. Both channels feed V4 for the reverb. So yes, its going to be noiser than its ancestor.
The best low noise tubes I have found are the Gold pin JJ ECC83s. They have low noise coatings. Get three for V1, V2, V3


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Sun Mar 03, 2019 8:21 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Fri Feb 06, 2015 10:21 pm
Posts: 393
Location: Oklahoma
My 65 Twin Reverb Reissue was doing the same thing right out of the box. With help from these forums, I isolated the problem to preamp V4, replaced it, and now it's quiet as a mouse.

This may be something different, but I can't see how anyone can say that's normal and it's OK?


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Sun Mar 03, 2019 9:37 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
I doubt that anyone at Fender, having a full understanding of the problem, said that it was normal. :roll:

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Tue Mar 12, 2019 9:13 am
Offline
Professional Musician
Professional Musician

Joined: Wed Aug 26, 2009 4:50 pm
Posts: 1339
Location: Denver, CO, USA
"I've taken the amp to the local official Fender amp repair person, and they got told the same thing by Fender (it is "normal") so they aren't helping."

Sorry for resurrecting the thread -- Tim's newer post about noise prompted me to read this.

The reverb mod may introduce some audible noise, but minor and nothing like this. It's a fairly common mod for regular DR's & DRRI's and no one ever complains about noise.
----------------------
Fender Support and the tech may have said it's not a warranty issue because it's tube-related and tubes have a shorter limited warranty, so he has to pay for a tube or tubes, and either install them himself or pay the tech to install them.

But as part of the tech's evaluation of the problem, I'm surprised that he didn't temporarily swap in known-good tubes to verify that it's a tube problem.

I only listened to part of the first clip, but that sounded bad enough to me that a solder joint or plate resistor could be involved.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Tue Mar 12, 2019 9:28 am
Offline
Professional Musician
Professional Musician

Joined: Wed Aug 26, 2009 4:50 pm
Posts: 1339
Location: Denver, CO, USA
But, gregorysean says it's had this noise from the beginning?

Possible. Tubes can be bad right out of the box, or suddenly go bad inexplicably.

But it stretches my credulity that anyone would plug into a brand new amp, hear that noise, and just live with it for a while.
--------------------
I bought a Kustom Coupe 36. Had played one previously so made the mistake of not testing the one I bought -- the only one the store had.

Got home, plugged it in, and it sounded like the first clip. Drove it back to the store. They swapped out the tubes, no better.

So they ordered another one, and sent that one back. Had to wait a week for the new one, and tested it in the store before taking it home. But that one was very quiet.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Tue Mar 12, 2019 10:34 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26415
Location: Tombstone Territory
strayedstrater wrote:
The reverb mod may introduce some audible noise, but minor and nothing like this. It's a fairly common mod for regular DR's & DRRI's and no one ever complains about noise.

+1

I'm also planning to perform this alteration (aka the "Fritz" mod) on my TRRI the next time I pull its chassis for routine PMCS. This was one of the first things I did to my '93 DRRI and I've never regretted it. And in my case the S/N ratio was unaffected.

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: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Sun Mar 31, 2019 9:40 am
Offline
Hobbyist
Hobbyist

Joined: Sat Apr 21, 2018 7:51 pm
Posts: 14
This is the exact noise my Custom 68 Deluxe Reverb is making. I bought mine June 2018. Please let me know what steps you took to get it fixed.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Tue Apr 02, 2019 11:07 am
Offline
Hobbyist
Hobbyist

Joined: Sat Apr 21, 2018 7:51 pm
Posts: 14
Hello. I am having the exact same problem with my amp as the OP. I also have a Custom 68 Deluxe Reverb Reissue. I followed the instructions on this site to see if a tube may be a problem.
https://www.sweetwater.com/sweetcare/ar ... nder-amps/

I took out v1 and v2 and the sound was still there. I took out v4 and the sound went away, but neither the vintage or custom channels worked, so I wasn't sure if that fixed the problem. Since both v2 and v4 are 12AX7A, I put the one from v2 in v4. That has seemed to solve the problem, and I can still use the custom channel.

I have never messed with tubes. Does this seem to all of you a good way of diagnosing the problem? Will switching the tubes like that cause any problems for the amp? Do I need to be in any hurry to replace the tube for v2?

Since I will eventually be in the market for a new tube, should I be looking to get an upgrade? It currently has Groove Tubes? And, since one went bad, does that mean I should go ahead and change all of them?

Like I said, I've never messed with tubes. Thanks for any help.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Tue Apr 02, 2019 10:14 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Hey John,

Swapping tubes is a great troubleshooting step, and you are right that since both are 12AX7, they can be swapped with no detriment to the amp. Different tubes of the same type (12AX7 for example) can sometimes have slightly different gain/sensitivity, some better for clean, some better for earlier breakup. Some tubes are better in certain positions in the amp.

Another way is to substitute one known good tube, into each position, one at a time to see if the problem goes away (using same tube type, 12AX7, 12AT7, etc). That way you can pin down the exact tube that has issue. No need to replace all tubes when one is bad.

Note that V2 is used only for the Vintage channel, whereas V4 is used for both channels and reverb recovery. Is there any more of the noise that you heard before the swap, was it only on one channel, or both?

V1 for the Custom channel 12AX7
V2 for the Vintage channel 12AX7
V3 reverb driver 12AT7
V4 for both Channels, and reverb recovery 12AX7
V5 for Tremolo 12AX7
V6 phase inverter 12AT7

V7, V8 output tubes, if these tubes ever need replaced, it should be as a matched pair, and biased properly.

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Wed Apr 03, 2019 6:54 am
Offline
Hobbyist
Hobbyist

Joined: Sat Apr 21, 2018 7:51 pm
Posts: 14
Shimmilou - Thanks for the info. As of yesterday the noise was gone. I will spend more time with the amp today to make sure. The noise was on both channels. None of the knobs had any effect on it, and it did not matter if the guitar was plugged in or not. For now, I am fine with only having the custom channel as long as there is no noise. I will purchase another tube eventually. Maybe I'll wait until another one goes bad, then I look into getting a new set of tubes. I've noticed through some of my research that there are some tubes that are considered upgrades. I'll need to look into that a little more.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Wed Apr 03, 2019 8:10 am
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Sounds like this could also be cold solder or bad internal component connections. Maybe, in the power supply area.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Wed Apr 03, 2019 9:42 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
JohnStrat wrote:
Shimmilou - Thanks for the info. As of yesterday the noise was gone. I will spend more time with the amp today to make sure. The noise was on both channels. None of the knobs had any effect on it, and it did not matter if the guitar was plugged in or not. For now, I am fine with only having the custom channel as long as there is no noise. I will purchase another tube eventually. Maybe I'll wait until another one goes bad, then I look into getting a new set of tubes. I've noticed through some of my research that there are some tubes that are considered upgrades. I'll need to look into that a little more.


All things considered, seems like the tube that was in V4 (now in V2) might be the culprit, since noise was in both channels. Maybe that tube worked better in V2 position?

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Wed Apr 03, 2019 10:46 am
Offline
Hobbyist
Hobbyist

Joined: Sat Apr 21, 2018 7:51 pm
Posts: 14
I have had my amp on for over an hour and the sound has not come back. Before it would start after about 5 minutes.

Shimmilou- I think you are correct. I believe it was the tube in V4. I took the tube from V2 and put it in V4. I don't have anything in the V2 position. Everything is working fine except I cant use the vintage channel. That is fine for now. I mainly use the custom channel anyway.

Thanks for your help.


Top
Profile
Post subject: Re: Crackling/Scratching idle noise on Deluxe Reverb Custom
Posted: Thu Apr 04, 2019 4:36 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Fri Feb 06, 2015 10:21 pm
Posts: 393
Location: Oklahoma
JohnStrat wrote:
I have had my amp on for over an hour and the sound has not come back. Before it would start after about 5 minutes.

Shimmilou- I think you are correct. I believe it was the tube in V4. I took the tube from V2 and put it in V4. I don't have anything in the V2 position. Everything is working fine except I cant use the vintage channel. That is fine for now. I mainly use the custom channel anyway.

Thanks for your help.
In my previous post, I mentioned it sounded like my TRRI's problem (V4) and it looks like it was. I hope so. A couple years later, my reverb was freaking out and I used the same method to replace a V3 tube. The others should be fine, until they're not. :)


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 20 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: TimsAudio 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: