About to add a Hammond Filter Choke to DSL100HR 3H or 5H which do you prefer?

[Michael Inglis]

So I would have done this sooner but I wanted to wait out the majority of the warranty. From what I gather the 3 Henry 250ma (194G) is more modern sounding/feeling. I dont know if I'm going to prefer a choke either so I'll save the resistor and actually remove the leads, I do A LOT of soldering so it shouldn't be too much trouble. And I'm going to remove the whole PCB anyways so I can mount the Choke where it looks right. If the mounting screws are too close I'll dremel the excess and insulate them just in case.

I do pedal builds from scratch (sometimes even my own circuits, I just finished a Chasm Reverb with some mods I came up with that I think are really great improvements), build guitars from scratch and do all sorts of mods. I know my way around a soldering iron well and I respect the voltages amd more precisely implied current found inside tube amps. Which is more than I can say for most people i see posting about doing mods to their amps on here lol.

So its between the 194G (3H 250ma Plexi Choke) or the 194F (5H 120ma, JCM800 choke). Any advice or experiences would be GREATLY appreciated. If I find that I do prefer a choke to a low pass filter/resistor then I'll likely upgrade it later and maybe do the OT as well. Thanks for the help!


EDITS:

11/29/21-

I just finished installing the 194G choke and it went in without too much trouble. I removed the board which was the only real pain in the ass. But im glad i did because it allowed me to place the choke where i wanted and do it carefully. It also gave me a chance to look over the board and i found that the outer most 1K 5W screen resistor closest to the edge of the board (its either R48 or R19 based on the schematic) was rocking from side to side with just a slight touch. So I reflowed the joint and added some fresh solder, good as new.

I removed the old resistor where the choke leads went properly and used a solder sucker to clear the through hole so i could place the choke leads in from the back side. That part went very smoothly. Next i drilled my holes for the choke and for the grommet and mounted the choke. I dont have any lock washers that fit #32 machine screws so i just used blue loctite. And the #32 screws are only 1/2" so im not worried about them touching the backside of the board.

Its worth mentioning that you could absolutely mount the choke without pulling the board by mounting it in-between the bias point board and the main board. But for anyone hoping to just clip the resistor off and solder to the leftover posts like most people did on the 100H im sorry to say you most likely will find that impossible due to the fact that the filter caps are surrounding it. But its best to remove the resistor correctly anyways incase you find you prefer the sag/feel of no choke etc.

Its late and my girl is already asleep so i wasnt able to turn the amp up loud enough tonight to see how the noise floor is and how the amp reacts when dialed into the sweet spot volume wise. Just loud enough to verify everything is working as it should. So tomorrow ill double check that the bias is where it should be (i already checked tonight right after turning on the amp but i might adjust it tomorrow after the amp really warms up since i think its slightly higher than ideal but its hard to say without letting it fully warm up).

Ill do another post with the install process more in depth but for now heres some pictures of how it came out and where i decided to place the choke.

 

[South Park]

Take a look at what size filter caps you have the two work together . If you go with a higher resistance choke you might get some voltage sag or loose some gain and tone it is a crap shoot what you get . Murcury magnets makes a multi tap choke . You really can’t match other amps on this one you just have to go for it

 

[Michael Inglis]

Take a look at what size filter caps you have the two work together . If you go with a higher resistance choke you might get some voltage sag or loose some gain and tone it is a crap shoot what you get . Murcury magnets makes a multi tap choke . You really can’t match other amps on this one you just have to go for it

After some more research it seems like the 3H plexi type choke would probably be best suited to this amp (mouser has its DC resistance listed at 79.92k). Thanks for the info about the multi tap choke from M.M. i wasnt aware they or anyone else made one, seems like a really practical idea.

 

[K2JLX]

Pls share pictures of the install when you install the choke, I’m thinking about putting one in mine.

 

[burger]

My clip on this might be helpful,



I used a jcm800 choke, however a 3hy plexi choke would be great also.

 

[Chris-in-LA]

So, in the video he uses 2 different guitars and plays completely different passages and goes on to tell us that it feels better to him. The part after the addition of the choke sounded like a buzzy mess to me.

 

[Michael Inglis]

My clip on this might be helpful,



I used a jcm800 choke, however a 3hy plexi choke would be great also.

Hey the man himself! Ive actually already seen that video and several of your others a few times in fact (i found them researching this topic). Subscribed to your channel on youtube recently a few days ago. Great content, keep it up. As for the above comment...

You can NEVER make everyone happy on the internet. People seem to forget humans arent perfect and wont ever be able to do things perfectly to please everyone the second they get online lol. Anyways i really like your videos and i think that particular one is very well thought out as are the other ones ive seen. I saw it for what it was, a video with the intent of teaching others how and why to use a choke. That seemed like its primary purpose, not to do meaningless before and after clips that after youtube compression wouldnt mean shit anyways.

 

[Michael Inglis]

Pls share pictures of the install when you install the choke, I’m thinking about putting one in mine.

Will do, im working on it today.

 

[Michael Inglis]

My clip on this might be helpful,



I used a jcm800 choke, however a 3hy plexi choke would be great also.

Pls share pictures of the install when you install the choke, I’m thinking about putting one in mine.

Just added some pictures to the original post. Ill make a whole post in the next day or so about the install in more depth. So far so good, i wont be able to turn it up and see it i notice a difference till tomorrow. But for now from what i can tell it certainly didnt make it worse. I loved the amp without the choke but thought it couldnt hurt to improve the noise floor an lessen the sag a bit at higher volumes. Its certainly quiet but its always been quiet ever since i changed the tubes right after i got the amp a launch to EHX el34's and a couple of the preamp tubes (Mullard CV4004 in V2 and Tung sol in V4/P.I. and kept the stock JJ ecc83 low noise in V1 and Shuguang rebranded "Marshall" ECC83/12ax7 in V3). Ive rolled a ton of preamp tubes and power tubes in this amp and thats what i keep coming back to.

 

[burger]

So, in the video he uses 2 different guitars and plays completely different passages and goes on to tell us that it feels better to him. The part after the addition of the choke sounded like a buzzy mess to me.

So, happy life?

 

[burger]

Hey the man himself! Ive actually already seen that video and several of your others a few times in fact (i found them researching this topic). Subscribed to your channel on youtube recently a few days ago. Great content, keep it up. As for the above comment...

You can NEVER make everyone happy on the internet. People seem to forget humans arent perfect and wont ever be able to do things perfectly to please everyone the second they get online lol. Anyways i really like your videos and i think that particular one is very well thought out as are the other ones ive seen. I saw it for what it was, a video with the intent of teaching others how and why to use a choke. That seemed like its primary purpose, not to do meaningless before and after clips that after youtube compression wouldnt mean shit anyways.

Thx Michael! Honestly I don't know why I bother posting in these forums.

 

[Michael Inglis]

Thx Michael! Honestly I don't know why I bother posting in these forums.

So, happy life?

LOLOLOLOL

 

[Michael Inglis]

Thx Michael! Honestly I don't know why I bother posting in these forums.

Had i not seen your video already it would have been exactly what i was looking for. Not everyone here is a jackass, in fact most of my experiences on this forum in particular have been good. But every now and then youll get a comment from some guy who thinks post count equates to superior knowledge of everything under the sun. But im sure you already knew that and your comment wasnt literal.

 

[Chris-in-LA]

So, happy life?

Sure. My point was it would be nice to do the demo with the same guitar playing the same passages, that would be a more valid comparison. The way the video was done it was impossible to know why the two demos sounded different. I thought that was the point, to show the difference between having a choke or a resistor.

 

[burger]

Isn't this exactly what I am doing at the 1:14 mark?

I even did it via a recorded loop, which was played back through the amp with No Choke & then with the Choke. i.e. an A/B sound test with all other variables eliminated.

 

[2L man]

I think 3H 250mA Choke should be placed before Output Transformer/Plates to get best effect out of its high current rating. Its current rating is too high for Screens and Pre Amp and there 20H 50mA should be used.

 

[Chris-in-LA]

Isn't this exactly what I am doing at the 1:14 mark?

I even did it via a recorded loop, which was played back through the amp with No Choke & then with the Choke. i.e. an A/B sound test with all other variables eliminated.

What are you doing at 1:14? I didn’t see any looping, I saw you playing an S type guitar that sounded great.

 

[Pete Farrington]

I think 3H 250mA Choke should be placed before Output Transformer/Plates to get best effect out of its high current rating. Its current rating is too high for Screens and Pre Amp and there 20H 50mA should be used.

At high power output levels, a 4xEL34 amp will tend to have a HT current draw somewhat above 250mA.
EL34 screen grids can draw a lot of current when overdriven, hence a 50mA max choke could have its magnetic circuit saturated and so lose its inductance, just when it’s needed most. Especially so in a 4xEL34 amp.

Edit: I checked the HT current drawn by my ‘JTM50 with GZ34 kinda build’, when overdriven it was nearly 350mA DC!

 

[Michael Inglis]

At high power output levels, a 4xEL34 amp will tend to have a HT current draw somewhat above 250mA.
EL34 screen grids can draw a lot of current when overdriven, hence a 50mA max choke could have its magnetic circuit saturated and so lose its inductance, just when it’s needed most. Especially so in a 4xEL34 amp.

Edit: I checked the HT current drawn by my ‘JTM50 with GZ34 kinda build’, when overdriven it was nearly 350mA DC!

This

 

[burger]

What are you doing at 1:14? I didn’t see any looping, I saw you playing an S type guitar that sounded great.

Apologies if it's not clear. What I did was to film that riffing while playing into the AXE FX's looper. Then re-amped that (long) loop back though the amp before and after the choke mod. The two audio tracks are then synched with the video, and I'll toggling back and forward between the two audio tracks for the A/B. This is why on screen it says "No Choke" then "Choke", and so on.