ARS filter caps, what to expect?

BesaMoogie

BesaMoogie

Well-known member
So I`m currently working on a DIY 2203 clone and trying to tweak it to my liking. Doing this, I am comparing it to my JCM800 2204 from 82.

On thing that bothers me is, that I can`t get the lowend to respond the way I would like. There seemed to be a layer of low harmonics giving the lowend a rather spongy/saggy feel and taking away the grind I get from my original 2204. The lowend on the 2204 is focused, percussive and fast whereas the clone has more of a bouncing thing going on. I immediately relax my picking hand, when switching to the 2204 whereas with the clone, I compensate the saggy response by picking and muting harder. Me don`t like this.

I made a "clipping system" on the turret board and already played around with different cap brand (NOS Philips MKT, Sozo, Mojo, Ceramics, Mallory) as well as with different resistor meterials (CC,CF,MF) with some improvement, but I am starting to think, that maybe the filter caps are the missing link in this?
The clone has currently TAD filter caps which are their take on the LCRs, but they are from a different manufacturer than ARS.

The clone has a PV of 450V and an OT made by Dagnall. The JCM800 2204 has a lower PV of 390V, but still feels more percussive.
Tubes in the preamp are the same on both amps, the 2204 has TungSol EL34, the clone has TAD el34.

So people with experience on ARS filter caps, please chime in. Why do you like or dislike them and how did they affect the response and tone in your amps?

PS: when done with this project, I am planing to make a thread about the findings I made during the build.
 
Not much help but I replaced the LCR’s in my 2204 with ARS and the main difference I notice is the amp is quieter. I also changed the input wire to a grounded one which REALLY quieted the thing down as it was intolerably noisy with the gain up. In all of that it would be hard for me to hear a subtle difference in the low end but all I can say is the thing sounds great now. I did question whether I should have replaced the LCR’s since most of my noise problem was from the input signal but I really have no complaints.
 
For the most part, people don’t hear a change with filter cap brands. I and a few others do, however. My experience is with an 87 2555, and an 82 2204. Both had this grainy texture to the tone; I thought the 2555 had been modded. Sold it. Grabbed a 2204 from 82, same grainy thing. Both amps had F&T filter caps. Read about ARS being clones of the LCRs. Bought a pair and swapped them in place of the F&Ts.
That solved it! For me anyway.
So I would say that ARS caps will sound just like the LCRs you replace. Or Dalys for that matter.
 
If you’re modding the circuit then you also could have instability present causing inaudible oscillations that can manifest themselves oddly in the audible band. Filter cap BRANDS are a third order effect after size and layout of your preamp.

I suggest instead of modding an amp hap hazardly which is dangerous, I suggest you read up on electrical engineering theory first. These amps are not toys and can kill you if you don’t know why and what you’re doing.
 
ARS caps are great. Now will they remove your flub problem, unlikely. The cap values have much more effect on that, also the length of the wire from the cap to your board. I can hear a difference from mounting the preamp filter caps directly on the board, vs them being mounted on the chassis.

I've also had preamp tubes cause the flub, you might swap the set from your 82, and try.
 
Had ARS 50/50 caps in my Marshall, later changed them out to F&T.
Both good quality.

UA8GQ7Il.jpg
 
Racerxrated said:
For the most part, people don’t hear a change with filter cap brands. I and a few others do, however. My experience is with an 87 2555, and an 82 2204. Both had this grainy texture to the tone; I thought the 2555 had been modded. Sold it. Grabbed a 2204 from 82, same grainy thing. Both amps had F&T filter caps. Read about ARS being clones of the LCRs. Bought a pair and swapped them in place of the F&Ts.
That solved it! For me anyway.
So I would say that ARS caps will sound just like the LCRs you replace. Or Dalys for that matter.
Click to expand...

It's def a combination. This is why amp techs exist. So any of these reasons could be the reason:

- Output tube bias (cold-Med-Hot)
-Output tube type ( some just bring the goods better than other and handle low end differently)
- preamp tube choice
-component drift or choice of values ( varied slightly in amps especially with carbon comp)
-filtering
-transformer
-preamp tweaks causing too much bass
- Negative Feedback resistor - Loose ass to tight young thang depending on value.


All these things are what make your either : underwhelming, good, really good, amazing, or HOLY $HIT HoLy GrAiL Marshall.

When they mention the Purple Plexi or Ed's 1 and 2, that is why. These are the amps where everything just worked together to create that sound.
 
Kapo_Polenton said:
I'm thinking the transformer may be the bigger factor here. What's the diff in Iron between the two?
Click to expand...
The JCM800 2204 has all the original Drake iron with the PT being the lower volt version.
The clone has a TAD PT with 450 volts PV, TAD OT which is made by Dagnall and is a clone of a 68 Plexi OT and a Hammond choke (194B, 4H @ 90mA DC).
 
glpg80 said:
If you’re modding the circuit then you also could have instability present causing inaudible oscillations that can manifest themselves oddly in the audible band. Filter cap BRANDS are a third order effect after size and layout of your preamp.

I suggest instead of modding an amp hap hazardly which is dangerous, I suggest you read up on electrical engineering theory first. These amps are not toys and can kill you if you don’t know why and what you’re doing.
Click to expand...
The clone is a stock 2203 circuit now (again).
At one point, I tried lower values in the cathode bypass of V1B as well as cutting bass at the first coupling cap (0.022 --> 0.0022) and increasing bass again with a fixed NFB depth circuit which came closest to what I liked. The bass was tighter overall but the immediate attack was not there. Again, when palm muting, I instantly start to cramp my hand and start hitting the strings harder. Changing the NFB to different OT tabs did not help either.
Measuring the voltages in the preamp, the clone had about 5 volts less on the plates.

What do you mean by preamp layout? I use a turret board and followed the basic lead dress rules like twisting all AC supplies and keeping them away as far as possible from signal carrying components, signal carrying leads usually cross in a 90 degree angle etc.

PS: maybe my question sometimes come off as goofy, but that`s mostly because english is not my first language. Be assured, that I take care about safety and always drain the filter caps, before working in amps.
 
BesaMoogie said:
The clone is a stock 2203 circuit now (again).
At one point, I tried lower values in the cathode bypass of V1B as well as cutting bass at the first coupling cap (0.022 --> 0.0022) and increasing bass again with a fixed NFB depth circuit which came closest to what I liked. The bass was tighter overall but the immediate attack was not there. Again, when palm muting, I instantly start to cramp my hand and start hitting the strings harder. Changing the NFB to different OT tabs did not help either.
Measuring the voltages in the preamp, the clone had about 5 volts less on the plates.
Click to expand...
If you want immediate attack try dropping the stock 68k input resistor to 10k
BesaMoogie said:
What do you mean by preamp layout? I use a turret board and followed the basic lead dress rules like twisting all AC supplies and keeping them away as far as possible from signal carrying components, signal carrying leads usually cross in a 90 degree angle etc.
Click to expand...
Adding more components than what come stock. Lead dress, lead length, solder type, type of wire, gauge of wire, whether it’s shielded coax, all can negatively affect amp stability and/or sonic performance in some manner. As mentioned prior it’s the summation of many things that make up an amps sound and not just one thing specifically.
BesaMoogie said:
PS: maybe my question sometimes come off as goofy, but that`s mostly because english is not my first language. Be assured, that I take care about safety and always drain the filter caps, before working in amps.
Click to expand...

Please always make a plan as to what you’re going to do in the chassis when it’s live, do that plan, and if it doesn’t work as you expect, turn it off, drain the caps, and reassess with another plan.
 
Kapo_Polenton said:
It's def a combination. This is why amp techs exist. So any of these reasons could be the reason:

- Output tube bias (cold-Med-Hot)
-Output tube type ( some just bring the goods better than other and handle low end differently)
- preamp tube choice
-component drift or choice of values ( varied slightly in amps especially with carbon comp)
-filtering
-transformer
-preamp tweaks causing too much bass
- Negative Feedback resistor - Loose ass to tight young thang depending on value.


All these things are what make your either : underwhelming, good, really good, amazing, or HOLY $HIT HoLy GrAiL Marshall.

When they mention the Purple Plexi or Ed's 1 and 2, that is why. These are the amps where everything just worked together to create that sound.
Click to expand...
Well, I agree to a point. Yes, it all matters, of course. But, in my case, after having owned 50+ stock/modded Marshalls at that time, the common denominator was using F&T filter caps. Between both the 2555, and the 2204. The tone/gain had this obvious grainy quality to it, I hadn't ever heard before. Almost a choppiness. And, when I changed the F&T out for ARS, that choppiness completely disappeared. So, for me it's very obvious that using F&T filter caps caused that aspect I was hearing, in the tone of those 2 vintage Marshalls. Since removing the F&T solved it. And, I'm not the only person on this forum to notice that with older Marshalls + F&T caps.
Not saying they are bad caps, but to my ears when used in an old Marshall, they produce a quality to the tone that I don't care for. And, switching to ARS completely solved it/made the amp sound like it was supposed to, like all the 50-60 others I've owned, all with original LCR/Daly caps.
 
CrazyNutz said:
ARS caps are great. Now will they remove your flub problem, unlikely. The cap values have much more effect on that, also the length of the wire from the cap to your board. I can hear a difference from mounting the preamp filter caps directly on the board, vs them being mounted on the chassis.

I've also had preamp tubes cause the flub, you might swap the set from your 82, and try.
Click to expand...
I already made a whole preamp tube swap from one amp to the other, so at least, this can be excluded
 
Kapo_Polenton said:
It's def a combination. This is why amp techs exist. So any of these reasons could be the reason:

- Output tube bias (cold-Med-Hot)
-Output tube type ( some just bring the goods better than other and handle low end differently)
- preamp tube choice
-component drift or choice of values ( varied slightly in amps especially with carbon comp)
-filtering
-transformer
-preamp tweaks causing too much bass
- Negative Feedback resistor - Loose ass to tight young thang depending on value.


All these things are what make your either : underwhelming, good, really good, amazing, or HOLY $HIT HoLy GrAiL Marshall.

When they mention the Purple Plexi or Ed's 1 and 2, that is why. These are the amps where everything just worked together to create that sound.
Click to expand...
Tubes are biased in both amps at about 60-65% within the variance of the duet/quartet. Of course, this is taking the different PVs of the amps into account. Preamp is not tweaked and the NFB resistor is 100k wired to the 4ohm tab. At one point I had it wired to the 8ohm tab.

The clone started out with all CC resistors and Mojo Dijon caps and was worlds apart from the original 2204. The bottom end and response reminded me of my Dual Rectifiers, but maybe a bit tighter? Changing the coupling caps to a mix of Sozo and Phillips MKT 344 and changing the pf caps from SM to ceramics did bring me much closer tone, but not feel wise.
I am currently changing the CC resistors in the B+ supply line as well as the anode plate resistors for Beyschlag MF resistors. I started early in the preamp and work my way through it. Slowly, the punch is coming.

But there`s still a layer of rather dark harmonics instead of grind that makes the bottom end of the JCM800 2204 so percussive and fast responding
 
Filter cap brand isn’t going to solve your problem.

First thing I’d check with your symptoms is preamp voltage. That makes a huge difference in feel, saggy vs punchy. Check it at the PI dropper just after screen supply on each amp.

Also compare voltages at every node after the PI dropper, PI plates, V2B plate, etc, etc down to v1.
 
glpg80 said:
Adding more components than what come stock. Lead dress, lead length, solder type, type of wire, gauge of wire, whether it’s shielded coax, all can negatively affect amp stability and/or sonic performance in some manner. As mentioned prior it’s the summation of many things that make up an amps sound and not just one thing specifically.
Click to expand...
I am using standard leaded solder. Heater wires are 18 AWG, AC wires are 20 AWG and signal wires are 22 AWG, all non-stranded push back cloth.
One thing I changed was using shielded coax wires from input to V1B and the gain pot to V1A.
I read somewhere, that the grounded chassis can influence signal carrying wires by acting similar to a cap and dampening highs. Maybe I am loosing some of the Marshall grind that way?
 
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