It is currently Mon Mar 16, 2020 6:22 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 9 posts ] 
Author Message
Post subject: Mid 2000's Hot Rod Deluxe Issue
Posted: Tue Oct 27, 2015 6:01 am
Offline
Hobbyist
Hobbyist

Joined: Thu Aug 23, 2007 10:33 pm
Posts: 5
I have a probably around 2005-2006 Hot Rod Deluxe. I bought it new in Pittston PA, and have had issues with the drive channel from the get go. If I turn the drive past 2, all I get is crazy feedback and squealing. the The store I bought it from (B and C Music, now The Music Scene. Same owner) gave me the run around so I never got it fixed. At the time I was really into Fuzz pedals and had a plethora so, I never really used the drive channel.

Fast forward, I wasn't playing in a band, so the amp sat virtually unused for an extended period. Come to now and I have been playing at least once a week with a group of fella's for the past 2 years. In the past few weeks my amp has developed a ringing/squealing sound. It does this even with no guitar cable plugged into the amp.

It gets louder as the amp warms up. It's almost unnoticeable at first unless I use a fuzz or overdrive pedal. But once it warms up it is very prominent. I will mention I still cannot use the drive channel, though now I would like to (A pedalboard is getting heavy to carry around all the time).

We have changed out all the tubes, and still have issues. My old band mate bought a Blues Deluxe the same time as me from the same store, and has had zero issues with his amp.

Any suggestions on what could alleviate the squealing sound? As I said, this is a new development over the past few weeks. The amp has always been well kept in a smoke free house, and has only even been gigged with a handful of times. It has seen a lot of practice time, but the spaces have always been pretty stationary, meaning we used the same place for extended periods of time and the amp stayed at the space. The past 5 years space has been my house the amp has only been outside my house once (We started as a few guys just playing once or twice a week, drinking a few "adult beverages").

Short of going in to debt taking it to a shop, is there anything I can do to fixe my amp? I would love to fix both the drive channel and the ringing/squealing issue, but at the very least I need to get rid of the ringing issue.

Thanks for any help you can give. And If you need more info, I will be more than happy to provide. I tried to include everything I could think of.


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Mid 2000's Hot Rod Deluxe Issue
Posted: Tue Oct 27, 2015 10:11 am
Offline
Hobbyist
Hobbyist

Joined: Thu Aug 23, 2007 10:33 pm
Posts: 5
I have been told to try swapping out the 12AX7 for 5751. I think I might give that a shot. Any thoughts?


Top
Profile
Post subject: Re: Mid 2000's Hot Rod Deluxe Issue
Posted: Tue Oct 27, 2015 10:41 am
Offline
Amateur
Amateur

Joined: Thu Aug 02, 2007 5:13 pm
Posts: 190
Location: Taxachusetts
Sounds like a Microphonic preamp tube, try swapping tubes around and see if it goes away, V1 is your most sensitive tube so start with that one... swap it with V3 or if you have some preamp tubes around use that.


Top
Profile
Post subject: Re: Mid 2000's Hot Rod Deluxe Issue
Posted: Tue Oct 27, 2015 10:56 am
Offline
Hobbyist
Hobbyist

Joined: Thu Aug 23, 2007 10:33 pm
Posts: 5
Thanks, I'll give that a shot when I get home from work.


Top
Profile
Post subject: Re: Mid 2000's Hot Rod Deluxe Issue
Posted: Wed Oct 28, 2015 3:29 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Hi jeffreyjgrant,

I agree, likely a microphonic tube.

My favorite tube lineup for the HRDlx is a 5751 in V1, a 12AX7 in V2, and a 12AT7 in V3. This makes for a cleaner clean channel, and a bit smoother drive channels.

_________________
---> "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: Mid 2000's Hot Rod Deluxe Issue
Posted: Wed Oct 28, 2015 9:45 am
Offline
Professional Musician
Professional Musician

Joined: Thu Aug 07, 2014 3:25 pm
Posts: 1023
The HRDX is a single channel amp that has another stage added when the Drive channel is used.
V2b is the only tube stage added to the daisy chain in Drive.
So if the symptom only occurs in the drive or More Drive channels, then V2 is the only tube candidate.
Your original post indicated that you had changed the tubes already. If it made no difference, then it's unlikely that it is a bad tube.
The ringing and squealing you describe is a feedback problem.
Since it's been a problem from new stock, it could be from a multitude of assembly problems, not just component failures. Ringing and squealing that is not caused by a tube can be from bad solder connections or defective components It's unlikely that it can be fixed without getting a tech involved.

It's possible it is coming from the reverb tank. If the output wires of the tank are on the end by the AC cord, it sould be picking up a feedback signal. Try turning down the reverb or unscrewi the bag and moving the tank away from the chassis to see if the squealing stops.
One thing a tech might check:
It's possible C35 or C36 in the power supply are bad, causing the signals to couple in the power supply, causing feedback.
These caps will measure good and look good. But, when you tug on the positive lead, it will pull out.
Good luck...


Top
Profile
Post subject: Re: Mid 2000's Hot Rod Deluxe Issue
Posted: Thu Oct 29, 2015 5:16 am
Offline
Hobbyist
Hobbyist

Joined: Thu Aug 23, 2007 10:33 pm
Posts: 5
Thanks for all the help and reply's. I get held up moving a friend for 14 hours yesterday so I have yet to be able to try swapping the tubes around. I did order some 5751's and they will be here Saturday.

The drive issue was there from the amp being new stock. The ringing/squealing sound is a new development. I don't think I mentioned that the tubes we swapped in were not new. They were from my friends newer amp. I think his 6L6's were practically brand new, but his preamp tubes were not.

I didn't think the ringing issue was feedback due to it being a new issue, and it does occur with or without an instrument plugged into the amp (even with no cable plugged in) and continues with all other equipment in the room off and having moved the amp around the room. from all the help here and the videos I have watched it does sound like my tube went microphonic. We must have just mix and matched them in such a way there was always a bad tube in my amp. Or one of his is also microphonic, and for some reason it is not as loud in his amp. And come to think of it, I don't actually remember putting my tubes in his amp. I think we just put his in mine. He did swap out his power tubes because he was not happy with the tubes that came in the amp.

My first thought was my H1 Strat was causing it, due the guitar being pretty well used now. The bridge PU has been sounding very thin and tinny. But I swapped out for several other guitars and the same issue kept up. The one consolation was that this past Monday my H1 sounded great.


Top
Profile
Post subject: Re: Mid 2000's Hot Rod Deluxe Issue
Posted: Thu Oct 29, 2015 8:52 am
Offline
Professional Musician
Professional Musician

Joined: Thu Aug 07, 2014 3:25 pm
Posts: 1023
Well, when I say feedback, I'm guess I'm not thinking acoustic feedback from a guitar. Rather an internal feedback where signals are mixing in places they don't belong.
This can occur when the power supply capacitors don't properly isolate the gain stages. The signal gets into the power rail and can feedback.
Also, grounding each stage is important to isolate circuits to prevent feedback..
IMO you've got some bad solder in the drive circuit around V2b


Top
Profile
Post subject: Re: Mid 2000's Hot Rod Deluxe Issue
Posted: Sat Oct 31, 2015 3:18 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Aug 23, 2007 10:33 pm
Posts: 5
Thanks for all the help. I got my new tubes in today. They came as I was walking out the door to go to the gym. I almost turned around ad went back inside! But, I put three new JJ 5751's in and re-biased the amp. The bias was on 65. I read the amp should be 70-90. I set it to 70 and BAM! All my problems were gone. No more ringing (defiantly was a microphonic tube), and I kicked the drive channel up to 5 and no feedback!

So again, a thousand thanks for the help. This was something that always scared the hell out of me, and I couldn't believe how easy it was.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

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: