Feel free to ask Myles

[simpleman3441]

Please check out my thread "15w 112 celestion vintage 30 problem" and give any input you might be able to offer. Thanks.

[harvey]

Harvey,

 

Has this Crate amp always had this problem? If not, replace the output tubes if more than a few months old as 50 watts out of a quad of EL84s is really pushing them far beyond their design limits.

 

Thanks Miles,

 

Yes, I believe it's had this problem for a while. That said, I think the power tubes are original! The strange thing is though, that plugging an external pre-amp into the effects loop - and straight into the power section - sounds fine.

 

Cheers,

[myles_rose]

Please check out my thread "15w 112 celestion vintage 30 problem" and give any input you might be able to offer. Thanks.

 

Please copy and repost here if you want me to look at your issue.

[myles_rose]

Harvey,

 

Has this Crate amp always had this problem? If not, replace the output tubes if more than a few months old as 50 watts out of a quad of EL84s is really pushing them far beyond their design limits.

 

Thanks Miles,

 

Yes, I believe it's had this problem for a while. That said, I think the power tubes are original! The strange thing is though, that plugging an external pre-amp into the effects loop - and straight into the power section - sounds fine.

 

Cheers,

 

Have somebody test all the tubes.

 

 

[simpleman3441]

I found a Fender Blues Jr. Emerald and was smitten with the way it broke up. It's a 15w with a celestion v30. This is my first experience with a low watt tube amp and I'm a little confused by a particular phenomenon that is occurring. There is this sort of flux sound that happens for short periods of time but only occasionally. Half the time it just sounds fantastic. Then for apparently no reason itll start doing this strange thing, almost trem-like but not affecting the volume. Its more of a variation in gain. I played it a few days ago to get a better feel for what's goin on and it was behaving differently than when I had played it last. I knew I wasn't crazy cause my girl was there and vouches for my description. This time when I played, it was making the noise consistently. It's a white noise and I didn't hear the tremolo thing I was hearin earlier. The noise isn't real loud and is actually a little quieter than the hum of my single-coils. Occasionally there are some squeaks and other strange inconsistencies. It's not even noticeable when I play the Gibson through it. I took it to work with me to use a different single-coil. I was wondering if there isn't something wrong with my Strat that isn't noticeable through the 50w Bassman I have. I had someone put Texas Specials in and I'm hoping it's not a problem there. At work, I tried it with my friends G&L. It sounded fantastic. I couldn't reproduce any of the noises that were happening in my room. My boss said it might be the type of lighting that I'm using in my room. So I brought it home and turned it on. Immediately it started doin the original flux thing I was talkin about. So I play it for a second to be sure then I turned the volume all the way down to walk over and turn off the light, and when I got back to my amp and turned it up again to play, the noise was gone. I flipped the light switch on again to see if it'd start up again and the noise didn't come back. I'm wondering if my inexperience with lower watt amps is the culprit. lol Is there a noise floor on amps that's higher with lower watts? Do low watt tube amps ever just make funny noises for a couple minutes while they warm up? Am I being paranoid? I'm reluctant to take it back and part with a good amp if this is just my ignorance. Advice, please.

[harvey]

Harvey,

 

Has this Crate amp always had this problem? If not, replace the output tubes if more than a few months old as 50 watts out of a quad of EL84s is really pushing them far beyond their design limits.

 

Thanks Miles,

 

Yes, I believe it's had this problem for a while. That said, I think the power tubes are original! The strange thing is though, that plugging an external pre-amp into the effects loop - and straight into the power section - sounds fine.

 

Cheers,

 

Have somebody test all the tubes.

 

 

Thanks Miles for your time and wisdom!

[myles_rose]

I found a Fender Blues Jr. Emerald and was smitten with the way it broke up. It's a 15w with a celestion v30. This is my first experience with a low watt tube amp and I'm a little confused by a particular phenomenon that is occurring. There is this sort of flux sound that happens for short periods of time but only occasionally. Half the time it just sounds fantastic. Then for apparently no reason itll start doing this strange thing, almost trem-like but not affecting the volume. Its more of a variation in gain. I played it a few days ago to get a better feel for what's goin on and it was behaving differently than when I had played it last. I knew I wasn't crazy cause my girl was there and vouches for my description. This time when I played, it was making the noise consistently. It's a white noise and I didn't hear the tremolo thing I was hearin earlier. The noise isn't real loud and is actually a little quieter than the hum of my single-coils. Occasionally there are some squeaks and other strange inconsistencies. It's not even noticeable when I play the Gibson through it. I took it to work with me to use a different single-coil. I was wondering if there isn't something wrong with my Strat that isn't noticeable through the 50w Bassman I have. I had someone put Texas Specials in and I'm hoping it's not a problem there. At work, I tried it with my friends G&L. It sounded fantastic. I couldn't reproduce any of the noises that were happening in my room. My boss said it might be the type of lighting that I'm using in my room. So I brought it home and turned it on. Immediately it started doin the original flux thing I was talkin about. So I play it for a second to be sure then I turned the volume all the way down to walk over and turn off the light, and when I got back to my amp and turned it up again to play, the noise was gone. I flipped the light switch on again to see if it'd start up again and the noise didn't come back. I'm wondering if my inexperience with lower watt amps is the culprit. lol Is there a noise floor on amps that's higher with lower watts? Do low watt tube amps ever just make funny noises for a couple minutes while they warm up? Am I being paranoid? I'm reluctant to take it back and part with a good amp if this is just my ignorance. Advice, please.

 

I would need to hear the amp. This can be many things including your guitar, cables, power, etc.

[simpleman3441]

Is there a noise floor on amps that's higher with lower watts? Do low watt tube amps ever just make funny noises for a couple minutes while they warm up? Am I being paranoid?

 

I guess I'll just assume that the answers to these questions are no, no, and yes. LOL Thanks for takin the time to read that long post. I knew it was probably one of those things that you'd have to hear. I'll prolly take it back to GC and see if they have one to exchange. Thanks again, though.

[myles_rose]

Amp noise floor has nothing to do with wattage. High front end gain amps generally can produce more background noise. Amp construction, design etc. all pose a factor. Funny noise? I would need an example but odd noises are not something that are expected. Funny noise on warmup is generally a tube issue.

[simpleman3441]

Thanks! I was able to exchange the amp so I'm hoping that takes care of the issue. I'll post again if it continues...

[myles_rose]

Thanks! I was able to exchange the amp so I'm hoping that takes care of the issue. I'll post again if it continues...

 

Happy playing.

[simpleman3441]

I just got a chance to plug in the replacement. It's not makin a single sound. I'm not even joking. Wish I were cause I really liked the tone of that amp. I'm sittin here with the smell of hot tubes in the room and every pot cranked to 12. Tried it with the fat switch on. Tried it with the fat switch off. Tried both my LP and Strat with two different Monster cables. Tried it on a different outlet in a different room and then again on the one in the room I'm in. Not a peep. I may have completely lost faith in Fender's production quality recently, unless you can convince me otherwise. What other amps I should try? I really liked the difference between the Emerald edition and the other Blues Jr. they had in the shop. I know one difference is that the Emerald has a Celestion Vintage 30 speaker in it. Is that what made the difference? Should I now be looking for an amp with that speaker? I know I want a low watt 112 if you have any suggestions that may give me a similar sound. I need something I can find ASAP and that costs less than a grand.

[myles_rose]

The speaker is no part of the problem. Get somebody with a degree of troubleshooting expertise to over see your actions. This sounds like an operator error so to speak but I have seen a lot of Fender production problems and QA issues You did not try out the replacement amp before bringing it home? That is a mistake as DOA stuff from shipping is not all that uncommon.

[simpleman3441]

I don't think the speaker was the problem. I was wondering if that's what was responsible for the difference in tone that I liked.

[myles_rose]

A speaker change makes a big difference in tone.

[simpleman3441]

So I've got good news. There doesn't seem to be an issue with the replacement amp. I had this funny feeling and rechecked the speaker connection. It was plugged in when I checked the first time. It's just that someone had plugged it in the footswitch jack. Seems to be good now.

[Caevan O’Shite]

Speakin' o' which...

 

Hey, Myles! I have this vague recollection of reading that some production amps or another were designed so that being run temporarily without a speaker (or at least a cable-plug) connected to the output-jack cut off signal to the output-section or some such safety/reliability measure.

 

Fender? Boogie? The Flying Dutchman?

 

Know anything about anything like that? Am I remembering right, or mixed up?

[myles_rose]

Hopefully the fellow above did not stress the output transformer as this is not a good thing to do at all. Some amps such as Rivera amps and some others have a special jack for the speaker that turns off the B+ when there is no speaker connected. Fender is NOT one of these.

[Caevan O’Shite]

Hopefully the fellow above did not stress the output transformer as this is not a good thing to do at all. Some amps such as Rivera amps and some others have a special jack for the speaker that turns off the B+ when there is no speaker connected. Fender is NOT one of these.

 

OK, so it was Rivera that I was thinking of; thanks!

[simpleman3441]

How can I tell if I did? Or do I just have to wait and see?

[myles_rose]

Just wait and see and figure you did not do any good to your output transformer that is one of the cheapest built transformers on the market. Down the road if you love the amp and want it to sound even nicer and be more reliable go to Mercury Magnetics and get one of their output transformers as a replacement. The transformers are the heart and soul of an amp.

 

In the future, ALWAYS assure the amp is connected to a proper load before taking it out of standby.

[simpleman3441]

Thanks. This is why I'm a part of this forum. No one would have ever told me any of this otherwise.

[myles_rose]

Happy playing.

[Tennessee]

I recently bought an older Peavey Delta Blues, a 210 model. Unfortunately, it had the reverb tank removed. The whole amp had been refinished, rather nicely, actually, sans the tank.

I decided to put in a new tank. Bought a tank, downloaded the schematics. Hoped to find the plugs up in the amp cavity, but there were just the four pins that the original plug attached to.

Looking the schematic over, (I'm an electrician, not electronic tech), I decided which represented the "hot leads" and which were grounds, so to speak. Since the reverb tank is essentially a pair of small coils with springs in the middle, I thought the only problem would probably be polarity of the coils.

I was right, my first attempt brought about a howling. Reversing leads made it work.

But mounting the tank, I got confused. I could not find the old screw pattern, so I just mounted it in the bottom of the combo as far away from the speaker magnets as possible. There is some hum, not bad, and it works.

Any guidance on where that tank actually sat in that box, and is the coil polarity a big deal?

Thanks

Tennessee

[myles_rose]

Rather than try to write this out I will say a few things ...

1. Assure that the reverb tank is the proper model.

2. The speaker magnets do not cause as much hum as the power transformer regarding placement.

3. Assure the proper cables and cable length to and from the tank.

4. Assure all parts of the circuit driving the tank and return of the wet signal are intact and proper spec parts. Perhaps the reason the tank was never replaced was due to an initial problem.

5. Polarity is important.

 

[Tennessee]

Thanks - tells me pretty much all I need to know. Never thought about the power transformer, hanging right out there.

And I will try reversing polarity on one coil, than the other, see if it quiets down more.

Tennessee

[myles_rose]

Good luck and I hope it all works out well.

[myles_rose]

Wondering if Tennessee's problem was resolved?

[siore]

Myles, is it safe to run a 12au7's heaters at 18v? The GE spec sheet says 12v, but I'm wondering if the tube has a tolerance for higher heater voltages. It's for a valvecaster (starved plate design boost pedal). Thanks.

[myles_rose]

Siore - well, if the pedal normally uses a 12AX7 and tolerates that without tube life too terrible the 12AU7 may follow the same sort of life curve. That is a LOT of heater voltage but perhaps the wiring config does not actually supply 18V but supplies 9v as the 12.6/6.3 12AX7 can be run at. Also, the plate voltage may be very low in a pedal as a step up circuit would be needed for any sort of battery operation.