# FIXED !! HRD hum/buzz on clean channel not 2nd channel ?



## Verne (Dec 29, 2018)

This is my first real tube combo amp. Love the tone and fullness of the sound, but a couple questions to see if it's normal, or I should take it in. I just got it one week ago at L&M and it is a trade in. When I turn it on, the upper right on the top of the amp vibrates slightly. Like a power vibration. Not excessive, but noticeable. When on there is a buzz coming through the speaker. It is not volume dependent. Volume off or full, and everywhere in between, the hum/buzz is consistent in it's "loudness". I get an audible hiss when turning the volume up, but I figure that's normal as it is knob position dependent. The buzz isn't really loud, but if I am 6-8 feet away I can hear it. Once I click the switch to channel 2, hum/buzz goes entirely away. I tried switching the first 2 pre amp tubes and no difference.I can't hear it when playing. Doesn't matter if I plug into either input, or if there is even anything plugged in. It just buzzes/hums. It is not a hiss, but either described as a buzz or hum. I plug into an ext cab and no difference. My H&K head makes no sounds other than the guitar. Is the power on vibration (like a transformer) and buzzing normal? Any troubleshooting ideas? Should I take it back and let them sort it? Sorry for the long post, but I wanted to describe it thoroughly so less time with questions about things I could post first off.


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## Verne (Dec 29, 2018)

I have tried plugging the amp into a different outlet with a high quality extension cord. I also tried plugging it into the outlet that the power bar is plugged into while the power bar was unplugged. Whether there is a cable plugged in or not, it has that constant hum on clean. Volume does not change at all. Different guitar plugged in makes no difference, but I really didn't expect it to if it hums with nothing plugged in.


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## Guest (Jun 22, 2019)

Verne said:


> Should I take it back and let them sort it?


Yes.


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## Verne (Dec 29, 2018)

When I turn the amp on, I can hear the hum. Much quieter as it is in standby, and not coming through the speaker. If I put my ear on the corner where the power/standby switches are, I can hear the hum. It's the same hum that comes out of the speaker in the clean channel (Ch 1). It's very much like a transformer hum you hear from those big green metal boxes on some peoples front yards.


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## Guest (Jun 22, 2019)

It may be the nature of the amp.
I had a HRD that did the same.
Bring it up with L&M.


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## Verne (Dec 29, 2018)

I am going there anyway today, so maybe I'll take it with me just for peace of mind. It's under 90 day warranty at least. Thanks good sir.


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## Verne (Dec 29, 2018)

It is being sent to be diagnosed and repaired. We compared mine to a new one in the store. It was fairly big difference in feeling a vibration near the on/off switch. New one is very slightly noticeable if you are looking for it. Mine is instantly noticeable. The hum I was hearing was replicated on the new one, but the volume had to be up at 6 or higher, mine was down near 2. Sooooooooo, it's going in. Thank goodness for 90 day warranty. They told me that one tube was glowing more brightly than the other as well. Who knows, maybe I'll get new tubes out of it as well. Either way, it'll be about a week if they don't need any parts ordered. *insert sad face here*

I have other amps, but as always, now that I can't........I want to play THAT ONE !!!


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## Distortion (Sep 16, 2015)

take it back it is something you are not going to be happy with. Try others in the store.


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## Verne (Dec 29, 2018)

It's not that I don't like the amp, it was making some noise it shouldn't be. It is being sent back under warranty for repair. I love this amp. I've been dreaming about this amp for 3wks. It'll be good as new when it is returned. I could live with the hum/buzz, but since it's covered, I am taking advantage of it.


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## Distortion (Sep 16, 2015)

Try a new one in the store so you know what they are suppose to sound like.


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## Verne (Dec 29, 2018)

Did that. There is a brand new surf green one we compared against. I did a recap post a few under my original. It is definitely not supposed to do what it's doing. At least not to the extent it is.


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## davetcan (Feb 27, 2006)

Told you that you should have bought mine 

btw, if I buy an amp from L&M I always get the 1 year warranty. It's not much and has saved me quite a bit a few times.


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## Verne (Dec 29, 2018)

In hind sight maybe the extended wasn't a bad idea. I've never needed it, but I suppose it'd never be a bad thing. It's just this one time I got "caught" with an issue, and hope it's the last.


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## J-75 (Jul 29, 2010)

I once bought a used DRRI in a parking lot, ie. without trying it out, based on good will and trusted reputation. I didn’t use it much, as I have “too many amps”. Each time I used it, it would serenade me with random hissing, coughing, farting, and sputtering plus hum. I felt I would look into it some day soon, but never got around to it. A few weeks ago, I was re-assessing it with a guitar, and unintentionally left it on for a day afterwards. It is now perfectly quiet, and behaves like a new amp.


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## Verne (Dec 29, 2018)

I figured with the 90 days I may was well take it in and have it checked. If it has been sitting unplayed, I was not aware, and likely the L&M staff didn't either. It was another known long term customer. If it still makes noise(s) when returned, maybe I will try the leaving it on idea. Was it truly in ON or in standby for the day it was left?


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## J-75 (Jul 29, 2010)

Verne said:


> I figured with the 90 days I may was well take it in and have it checked. If it has been sitting unplayed, I was not aware, and likely the L&M staff didn't either. It was another known long term customer. If it still makes noise(s) when returned, maybe I will try the leaving it on idea. Was it truly in ON or in standby for the day it was left?


I’m pretty sure it was ON. I don’t use standby much, and familiar with the power switch by feel (rightmost when facing the amp front).


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## oldjoat (Apr 4, 2019)

plug 'em both in ( and listen) before you take it home .
if it ain't fixed, they get to try again.


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## Verne (Dec 29, 2018)

Got my HRD back yesterday. Slip said replaced defective tube, and resoldered some stuff. Not only one tube was replaced, but all 5 were. The 5 that were in it, none matched. One power tube was a Groove Tube, the other I don't recall. The 12AX7 were one marked "china" (This was the defective one), one has no markings at all, the last is an Electro Harmonix. Now she's as quiet as a mouse down the street that you didn't know was even there. It sounds AWESOME as well. I do believe the new tubes have made it sound better than when I first got it. All new tubes are Sovtek. So, I got the amp inexpensive and now it's been fully serviced for free (thank you warranty) and it's life with me can now fully begin.

I also now have a couple 12AX7 to try out in my TM36. I know the 2 visible 12AX7 are generic "china" tubes, but I have yet to pull the aluminum sleeve off the first one. I was thinking of dropping the EHX in P1 and mess around with the other 2 spots with the last 3 tubes. I figure since I've got them, may as well try them.


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## GTmaker (Apr 24, 2006)

Why not try a 5751 in the V1 slot.....works great in all my amps...
G.


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## Verne (Dec 29, 2018)

I am not buying tubes, I can't at this point anyway, otherwise I'd buy a full set of both for the TM36. I already have the 12AX7's, so that's why I would mess with them. Some day I may retube the TM36 either when the extra $$ is there, or one (or 2) blow up. I don't dislike the tone the TM36 gives me, just wondered if a brand name tube in V1 is better than generic Chinese. As I said, I haven't taken that cylinder off the tube yet. I may over the weekend. I'll have a little time. May as well give it a go.
I have read more often that V1 changes the tone/sound of the amp over the rest. At least for the most part.


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## Verne (Dec 29, 2018)

GTmaker said:


> Why not try a 5751 in the V1 slot.....works great in all my amps...
> G.


Will this tube add or reduce gain? I do generally play clean, sometimes with a little grit, but overall clean is my most often mode. I am not opposed to trying something different, I just can't go out and buy it right now. Other things on the waiting list.


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## JBFairthorne (Oct 11, 2014)

Leave it to a guitar player to complain about a sound problem with his amp, get it fixed, rave about how amazing it sounds...and immediately start trying to find something to change hoping for an improvement. LOL. (Not at all meant as a jab).


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## Verne (Dec 29, 2018)

My last 2 posts were about the tubes in my TM36, not the HRD. I seriously LOVE the HRD tone and sound. It is just so damned full. The TM36 could now use a little love to keep it's status as my favourite. Chances are, "favourite" will change from week to week, or moment to moment. I'm sure I'm not the only one this applies(d) to.


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## GTmaker (Apr 24, 2006)

Verne said:


> Will this tube add or reduce gain? I do generally play clean, sometimes with a little grit, but overall clean is my most often mode. I am not opposed to trying something different, I just can't go out and buy it right now. Other things on the waiting list.


A 5751 preamp tube has 70% power of a 12AX7...
I find that it cleans up most tube amps nicely by reducing some gain which most tube amps have plenty of.
The slight gain reduction also makes a lot of that nasty hiss go away and allows for some real nice clean playing.

The only other thing I would add is that you seem to have plenty of tubes to play with and no way of knowing how strong those tubes are.
I happen to be lucky enough to have a tube tester but I realize that most folks don't have one.
Finding a way to get used tubes tested I think is a crucial part to getting an amp to sound great.
Weak tubes ( all tubes ) can be a silent problem that you will not be aware of unless these tubes are tested and verified that they are operating within specs.

G.


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## Budda (May 29, 2007)

For what its worth, some name brand tubes will probably be chinese.


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## Verne (Dec 29, 2018)

GTmaker said:


> Weak tubes


Yes, I thought of this. There may be a reason all tubes in the HRD were replaced, and not just the one. I also have no idea when the tubes in the TM36 were replaced. The power tubes were, but not the 12ax7 tubes. I can pop these in and see if there is any difference at all. If it's worse, take it out. Better....then I lucked out. No difference, spares. One way or another I am on the good end of the stick. Maybe L&M has a tester. I'll be stopping by there so maybe I'll take them with me.


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## Guest (Jul 13, 2019)

Verne said:


> *Maybe* L&M has a tester. I'll be stopping by there so maybe I'll take them with me.


Inquire first.
If they don't, maybe they can recommend a place?


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## Verne (Dec 29, 2018)

I’m going there today anyway. So it’s not out of my way. But I’ll post my “findings” when I get home.


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## oldjoat (Apr 4, 2019)

only about 3 factories that make "tubes" left in the world .

still lots of NOS tubes squirreled away.

so $$$ for a NOS Mullard / RCA , etc

and the boutique tubes are branded, for them, at one of the 3 production factories.


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## Verne (Dec 29, 2018)

L&M London south has no tube tester. It's not hard to just pop 'em in and out. If it storms later, gives me something to do. I was messing around with a HRD at L&M today, and the drive channel there sounded pretty good. I have my homework assignment now.


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## jb welder (Sep 14, 2010)

You don't really need a tube tester, you can use the amp. Just choose one spot (like the 1st position) and compare various tubes in there. Weak tubes (of same type ex. 12AX7) will give less output.


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## Verne (Dec 29, 2018)

I have nothing to lose by trying. Besides, it could have a good outcome. The HRD likely had tired tubes, and some could've been original from early 2000s hence the sounding way better after. I am not expecting miracles with the TM36, but a slight improvement is welcomed. Worst case, the tubes are retired and I have the same sound I bought the TM for.


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## Markus 1 (Feb 1, 2019)

Verne said:


> Got my HRD back yesterday. Slip said replaced defective tube, and resoldered some stuff. Not only one tube was replaced, but all 5 were. The 5 that were in it, none matched. One power tube was a Groove Tube, the other I don't recall. The 12AX7 were one marked "china" (This was the defective one), one has no markings at all, the last is an Electro Harmonix. Now she's as quiet as a mouse down the street that you didn't know was even there. It sounds AWESOME as well. I do believe the new tubes have made it sound better than when I first got it. All new tubes are Sovtek. So, I got the amp inexpensive and now it's been fully serviced for free (thank you warranty) and it's life with me can now fully begin.
> 
> I also now have a couple 12AX7 to try out in my TM36. I know the 2 visible 12AX7 are generic "china" tubes, but I have yet to pull the aluminum sleeve off the first one. I was thinking of dropping the EHX in P1 and mess around with the other 2 spots with the last 3 tubes. I figure since I've got them, may as well try them.



Just as a heads up in general
Very few tube factories exist these days.
Some chinese some russian and so on. So Groove tubes are re branded tubes that are tested for performance and matched. That said- I have had more than one brand new microphonic GT tubes when I used to service amps. I avoid them as a result and the price is another factor. Some Chinese tubes are great but you have to try them and learn from the experience.

Ruby Tubes in Ottawa? is a great supplier. He has very consistent quality

Hope it helps


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## Dorian2 (Jun 9, 2015)

I find I'm liking the EHX preamp tubes in my amps. Seem pretty solid and I like the sound. But I don't have a lot of experience with many others.


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## Verne (Dec 29, 2018)

I did put the EHX in V1 in my TM36. It wasn't a slap you in the face difference, but it was a slight difference. I liked the change enough to keep it there. I put the JJ in the 2nd slot as somehow I broke the tip off the chinese one without knowing and couldn't understand why my amp stopped working. Took a few minutes before I realized. It looked fine, but had the slightest crack in it. Now I know a little more about tubes. Thankfully I still had the 2 extras. All fine. I like the sound now. The TM36 sounds fuller and warmer to my ears. It has 4 Sovtek power tubes, so I'm leaving them alone. I did play around with positions and decided on what I have now in the TM36. The EHX is actually a 12AT7. Is that not a less gainy tube?


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## oldjoat (Apr 4, 2019)

yup


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## Dorian2 (Jun 9, 2015)

If you have a chance try a 12AY7 at some point. I think they're close to the least gainy. I use a 12AY7 in V1 on my Fender BJ as it gives it more clean headroom. Then the heavily OD'd pedalboard hits it when needed. Like always for my style.


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## Verne (Dec 29, 2018)

I will keep an eye out. I generally play clean most of the time anyway. I was like that when it was retubed, I got the old ones back. No idea how old this tube is, but I figured may as well try it. I like it.


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