It is currently Tue Mar 17, 2020 2:10 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 14 posts ] 
Author Message
Post subject: Hot Rod Deluxe Loud Hiss
Posted: Sun Jul 01, 2012 9:49 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
Hi Guys,
My Hot Rod Deluxe seems to have a very loud hissing coming from the Drive and More Drive. This amp is 6 months old and has very little use just being played at home so the volume hasn't been turned up at all.

I am now looking to gig with it and I am concerned this hissing is going to cause a problem.

I have set everything to 6 with Reverb at 0

Readings are

Drive 64db of hiss
More Drive 75db of hiss.

If I take the Master to 10 in the More Drive setting the noise goes up to 80db.

Clean channel is very quiet, not a problem.

This is without anything being connected other than the foot switch ( I have removed it to see if this is a problem and it didn't make any difference.)

This seams very loud to me, this can't be normal.

I have changed each of the 12AX7's starting with V1 through to V2 and V3. No difference. I have also changed the 6L6's with no improvement at all.

Any ideas.


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Sun Jul 01, 2012 10:18 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Hard to say what is normal, that sounds excessive based on your db numbers, but using the high gain settings at loud volume is going to produce a fair amount of hiss, it's a product of the high gain in this amp. Having the master and drive at 6 on the "more drive" channel will produce a lot of hiss, those settings are very loud. :shock: Once you start playing, you normally can't hear the hiss anyway. I can't recall anyone else actually measuring the hiss with a db meter, so I have no reference. How close to the amp were these readings taken? You should be approx 1 meter away from the amp for the readings. Adding pedals will usually increase the amount of hiss. You can try different tubes, some have less hiss, especially a lower gain tube like a 5751, and some tubes are specially selected for low noise. For the drive channel, V2 would have a greater impact only on that channel, little-to-no change to the clean channel. You also might want to check the lead dress from the power trans, proper dress here can also reduce the hiss. Mine, with leads dressed, on the clean channel, is as hiss-free as any tube amp can be, you have to put your ear right next to the speaker to hear it, and it's barely there. But, switching to drive channel adds hiss, and if I crank the volume the hiss increases. Lots of high-gain amps have some hiss, some worse than others. Noise/hiss comes along with gain on any tube amp, not much that you can do about it except reduce the gain, or use a noise-gate.

_________________
---> "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: Hot Rod Deluxe Loud Hiss
Posted: Sun Jul 01, 2012 10:33 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
shimmilou wrote:
Hard to say what is normal, that sounds excessive based on your db numbers, but using the high gain settings at loud volume is going to produce a fair amount of hiss, it's a product of the high gain in this amp. Having the master and drive at 6 on the "more drive" channel will produce a lot of hiss, those settings are very loud. :shock: Once you start playing, you normally can't hear the hiss anyway. I can't recall anyone else actually measuring the hiss with a db meter, so I have no reference. How close to the amp were these readings taken? You should be approx 1 meter away from the amp for the readings. Adding pedals will usually increase the amount of hiss. You can try different tubes, some have less hiss, especially a lower gain tube like a 5751, and some tubes are specially selected for low noise. For the drive channel, V2 would have a greater impact only on that channel, little-to-no change to the clean channel. You also might want to check the lead dress from the power trans, proper dress here can also reduce the hiss. Mine, with leads dressed, on the clean channel, is as hiss-free as any tube amp can be, you have to put your ear right next to the speaker to hear it, and it's barely there. But, switching to drive channel adds hiss, and if I crank the volume the hiss increases. Lots of high gain amps have some hiss, some worse than others. Noise/hiss comes along with gain on any tube amp, not much that you can do about it except reduce the gain.


Thanks for your reply, I had the meter about 2 feet away with no guitar or effects plugged into it. I suppose as I don't have anything to measure it against it sounds really loud in the confined space of my practice room, which is only about 9x7 feet.

My Blues Junior is a lot quieter but of course, this doesn't have the high gain option and as mentioned above, the clean channel is very quiet on my HRD.

I'll be able to try it out on Wednesday at the studio so this will hopefully give me an idea what it may be like when it's turned up a bit.

I read somewhere that valves have to be "burnt in" over a 48 period. Is this some old wives tail or is it suggesting things may quieten down once it's had a few ours of use.


Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Sun Jul 01, 2012 10:48 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Well, really, burn-in for tubes is mainly about reliability. Maybe a very slight change in sound after burn-in, but hiss will not get better. Speakers get better with use, but tubes generally do not.

If you are recording in a studio with the amp turned up that loud, you'll almost certainly need a noise-gate. I can already envision the engineer asking you to turn it down. :lol: I think that you'll get a much better recording if you use it at a more reasonable volume.

Definitely let us know the results, and settings that you end up using in the studio.

_________________
---> "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: Hot Rod Deluxe Loud Hiss
Posted: Sun Jul 01, 2012 11:35 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
Thanks shimmilou, I thinks that's the problem, I don't know how loud this amp will be, I look at 3 and think that can't be loud enough :D. I'll let you know how I get on Wednesday.


Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Mon Jul 09, 2012 2:35 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
shimmilou wrote:
Well, really, burn-in for tubes is mainly about reliability. Maybe a very slight change in sound after burn-in, but hiss will not get better. Speakers get better with use, but tubes generally do not.

If you are recording in a studio with the amp turned up that loud, you'll almost certainly need a noise-gate. I can already envision the engineer asking you to turn it down. :lol: I think that you'll get a much better recording if you use it at a more reasonable volume.

Definitely let us know the results, and settings that you end up using in the studio.



All is well at the Hot Rod camp. After a four hour session at the studio the HRD performed very well. Hissing wasn't an issue at normal studio and even higher levels. With all the ambient sounds around you from the rest of the band you don't notice any hissing.

It seems I may be selling some of my overdrive pedals as this little beauty has a fair bit of dirt for the type of music we play, which is blues, classic rock and some more up to date rocky stuff.

Thanks for your responses, much appreciated.


Last edited by Kluson56 on Mon Aug 06, 2012 5:31 am, edited 1 time in total.

Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Mon Jul 09, 2012 5:53 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
That's awesome, good to hear Kluson56. :)

But, for sale and wanted ads are not allowed on this forum.
http://www.fender.com/community/forums/viewtopic.php?f=1&t=4

_________________
---> "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: Hot Rod Deluxe Loud Hiss
Posted: Mon Jul 09, 2012 6:45 am
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
FWIW... "hiss" issue, if you want to pursue it --- is usually a pre-amp one. Most often centered around the input stage (V1). And mostly around the resistor types and dressing.

One thing that is easy to try. Heat and suck up ALL RoHS solder around the input tube. Replace with good quality tin/lead. RoHS is noted to add capacitance and uneven conductivity which can add noise.

For low noise and maintaining tone... I like carbon comp precision Riken or Kiwame resistors. These are stone quiet, good sounding resistors.

Here's a good article on resistors and noise:

http://www.aikenamps.com/ResistorNoise.htm


Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Mon Jul 09, 2012 9:42 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
shimmilou wrote:
That's awesome, good to hear Kluson56. :)

But, for sale and wanted ads are not allowed on this forum.
http://www.fender.com/community/forums/viewtopic.php?f=1&t=4



Apologies, didn't realise, should have read the link above first. :?


Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Sun Jul 15, 2012 9:24 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
BMW2002Ti wrote:
FWIW... "hiss" issue, if you want to pursue it --- is usually a pre-amp one. Most often centered around the input stage (V1). And mostly around the resistor types and dressing.

One thing that is easy to try. Heat and suck up ALL RoHS solder around the input tube. Replace with good quality tin/lead. RoHS is noted to add capacitance and uneven conductivity which can add noise.

For low noise and maintaining tone... I like carbon comp precision Riken or Kiwame resistors. These are stone quiet, good sounding resistors.

Here's a good article on resistors and noise:

http://www.aikenamps.com/ResistorNoise.htm


One of the great things about valve amps is the fact they are living breathing tone machines and as with anything breathing, they can be a bit temperamental, or at least my one is.

My original problem seems to have cleared up???? and I acquired a new problem which was a wooshing fluttering and crackling sound. This was only an issue in the clean channel of my HRD. Switch to drive and it stopped.

I checked through my limited supply of 12AX7's and found an old 1960's Brimar which I fitted into V1, replacing the GT which came as standard, problem appears to be sorted. :D :D :D

I can't believe a 50 year old valve performs better than a new one.


Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Sun Jul 15, 2012 2:12 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
That 50 year old tube likely never saw UPS.

You can edit your previous post to remove the ad. :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: Hot Rod Deluxe Loud Hiss
Posted: Mon Aug 06, 2012 5:34 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
shimmilou wrote:
That 50 year old tube likely never saw UPS.

You can edit your previous post to remove the ad. :roll:


Just a quick update on the hissing problem, I changed all three pre-amp tubes to JJ's and hissing in the clean channel has gone and it's very low on the More Drive. I didn't realise changing valves would make such a difference. :D

Thanks for your help.


Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Mon Aug 06, 2012 7:30 am
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Valves and a good contact cleaner = solving 90% of most amp issues.

:mrgreen:


Top
Profile
Post subject: Re: Hot Rod Deluxe Loud Hiss
Posted: Mon Aug 06, 2012 7:46 am
Offline
Hobbyist
Hobbyist
User avatar

Joined: Wed Feb 24, 2010 3:18 am
Posts: 52
BMW2002Ti wrote:
Valves and a good contact cleaner = solving 90% of most amp issues.

:mrgreen:


That's reassuring, when things don't sound right you tend to assume the worst and that it's the end of the world as we know it. Knowledge is power as they say. :twisted:


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 14 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: