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tse ii choke heat and buzz

brl0301

Member
2019-12-14 7:26 pm
I finished up my tseii build about a week ago and it is running and sounding great. I have a question about the choke though. It is buzzing loud enough to hear from 5 feet away. It is a mechanical buzz not through the speakers. It is also getting pretty hot after an hour or two of running the amp. Are these signs that there may be something wrong with the choke itself or maybe something wrong elsewhere on the amp? Im running 300b tubes at around 400v and 70ma of bias. I should be well within the specs of the choke. I also double checked the bolts holding the choke down and they are nice and tight.
 
Hi.

When i power my TSEII up, the choke is making some minor buzz around when psu is charging up. (Same things occur when using my variac when it reaches ~75% of the primary voltage)

Buzz is going away within 1-3 secunds, and stays silent.

This tells me, that it could be some part of the psu which causes this.
Also you could try squezing the chassis a bit to see if it makes any difference.
Regarding the choke temperature, the insulation is most proberly rated at Class F (125C.), so it can stand pretty much heat.

Jesper.
 

brl0301

Member
2019-12-14 7:26 pm
Hi.

When i power my TSEII up, the choke is making some minor buzz around when psu is charging up. (Same things occur when using my variac when it reaches ~75% of the primary voltage)

Buzz is going away within 1-3 secunds, and stays silent.

This tells me, that it could be some part of the psu which causes this.
Also you could try squezing the chassis a bit to see if it makes any difference.
Regarding the choke temperature, the insulation is most proberly rated at Class F (125C.), so it can stand pretty much heat.

Jesper.

what tubes are you running in your build and at what voltage? Also, what do you mean by squeezing the chassis?
 

brl0301

Member
2019-12-14 7:26 pm
Same setup as you, but B+ ~358.

Try to grap around the chassis and squeeze it different places.
To see/hear if it's resonance.

Jesper

Im wondering if maybe the higher voltage is more than what the cheap choke can handle. My chassis is an aluminum plate mounted on a wooden frame. I can feel the choke vibrating across most of the top plate and also in the power transformer as well.
 

brl0301

Member
2019-12-14 7:26 pm

brl0301

Member
2019-12-14 7:26 pm
Morning...

I cant tell if choke is overloaded at B+ 400v, but it looks like it's overloaded.
If possibly can you measure the mA running in choke with an multimeter? (Probes in serial connection with choke)

This way we can see if it's to close at the rated (200mA)

Jesper.

Good morning!

So I measured the current running trough the choke and Im getting 193ma with my wall voltage around 122vac. So I am pushing right up against the rated spec. My wall voltage also fluctuates quite a bit so Id imagine when its higher ( around 124) that its pushing the choke over spec. I also noticed that the choke buzz was slightly less with the amp tilted back. Im thinking that with the amp in its normal position, the noise gets trapped in the chassis and reverberates throughout the rest of the chassis.
 

Mr_Zenith

Member
Paid Member
2009-08-20 3:16 pm
KC Metro
Sounds like you've definitely have a mechanical issue. Several things can cause that, but it's usually either loose mounting, insufficient core constraint, or both. Those Triad chokes are OK, but they're built to a relatively low price point. See if you can swing something like a Hammond 159R (6 H @ 200 mA, 150 Ohms), as it looks like a drop-in replacement. Pay attention to mounting and I'll bet you'll hear a difference.

I'm using a Hammond 159Q (7 H @ 150 mA, 100 Ohms) on my 2A3 build and it's dead silent.
 

brl0301

Member
2019-12-14 7:26 pm
Sounds like you've definitely have a mechanical issue. Several things can cause that, but it's usually either loose mounting, insufficient core constraint, or both. Those Triad chokes are OK, but they're built to a relatively low price point. See if you can swing something like a Hammond 159R (6 H @ 200 mA, 150 Ohms), as it looks like a drop-in replacement. Pay attention to mounting and I'll bet you'll hear a difference.

I'm using a Hammond 159Q (7 H @ 150 mA, 100 Ohms) on my 2A3 build and it's dead silent.

Are the Hammond chokes considerably better quality? The specs and price are nearly identical, including the dimensions, which would make for a very easy swap. Ive double checked the mounting bolts and they are plenty tight so Im led to believe Im just overworking the triad choke. My concern would be that since the specs are the same that I would run into the same issue unless the Hammond is just a better quality product.
 

Mr_Zenith

Member
Paid Member
2009-08-20 3:16 pm
KC Metro
I can't be certain because I've never used a Triad choke. About all I can say is I've never had trouble with buzzing in a Hammond choke, even the open frame 15X series. For all I know the Triad choke could be a Hammond in disguise, but I doubt it as the core bobbin and wrap around the windings look different. But I agree with you that mechanical buzzing is annoying as h3!!.
 

brl0301

Member
2019-12-14 7:26 pm
I can't be certain because I've never used a Triad choke. About all I can say is I've never had trouble with buzzing in a Hammond choke, even the open frame 15X series. For all I know the Triad choke could be a Hammond in disguise, but I doubt it as the core bobbin and wrap around the windings look different. But I agree with you that mechanical buzzing is annoying as h3!!.

For the $20 it will cost it is worth the shot. Luckily I cant really hear the buzzing with music playing but its still annoying when I power up the amp. Do you get quite a bit of heat from your choke?
 

brl0301

Member
2019-12-14 7:26 pm
I use the same choke, but again my B+ is ~358.
Mine is dead silent also.

Looking forward to hear if another choke rated at same mA gives any difference?
I would search for some ~250mA min. if i was in youre place, but just my two cent's

Jesper.

I will keep this thread updated once I get the new choke ordered and installed. Hoping it does the trick as it would be an easy fix.
 
I measured the current running trough the choke and Im getting 193ma.....I cant tell if choke is overloaded at B+ 400v, but it looks like it's overloaded.

I have used the cheap Triad chokes to nearly 500 volts, so that's not the issue. A voltage related breakdown will not cause buzz, but can cause smoke, fire and other nasty issues. I have never seen an issue with the 20 or so off them that I have used over the years, but most of that experience came 10 or so years ago. I used to rip the frames off and put black end bells on them to clean up the ugliness, but the two that I bought last year lack the bolt holes in the laminations, so they obviously changed the recipe.

Excess current WILL cause buzz in a transformer, and might be an issue in a choke. Try dialing back the bias in the output tubes to see if it makes any difference.

For all I know the Triad choke could be a Hammond in disguise

Most of the Hammond stuff is made in Canada or Mexico. The Triads are Chinese. They don't look anything alike unless things have changed since I bought any. It's been a couple years since I bought any Hammond transformers.