Musicaps in a Dumble style build?

[10thTx]

Anyone hear tried building a Dumble style amp with Musicaps? Or used a few Musicaps in a few different spots like seasoning to cooking something?

I've done some experimenting with one of my D-inspired amps (the D'Mars) and found I like a few Musicaps in the mix.

And if you're using some other caps then Orange Drop or Musicaps, what are you trying in your D-style amps?

With respect, 10thtx

[Structo]

I assume you are talking about Hovland polypropylene music caps?
I've used them in guitar tone circuits but not amps.
I liked what I heard but in a guitar circuit it may not shine as well as in an amp.

What difference in tone do you notice with these caps?

[10thTx]

Here is my limited experience and subjective review.

My D'Mars ODS had almost all Orange Drop PS caps. I tried Musicaps in 5 different places replacing OD PS caps that I had in the amp. Earlier in the clean channel V1a and earlier in the OD channel V2b coupling caps made the most difference.

I was able to A/B the OD PS caps vs. the Musicaps back and forth around a dozen times around 20 minutes or more in each of those V1a and V2b positions. So all the caps replaced were one at a time with A/B listening except the post LTPI coupling caps.

More transparency, greater sustain (which surprised me) and smoother tone then the OD PS caps in V1a & V2b. This is the best my amp has sounded & the most touch sensitive in playing. I don't understand why there would be any increase in sustain at all, but that sounds like what I am hearing?

Post LTPI, they were just different and not "better" then the OD caps to my ears.

When playing a note with the OD PS caps, the notes seemed to have a sharper attack and decay quicker. The Musicaps have a warmer/rounder attack and sustain longer to my ears.

The downside is that while the Musicaps have a nice musical sweet tone, you lose the vowel tone compared to an OD PS. And they are $10+ each but if you're only using 2 or 3 for "seasoning" then that's not too bad. They are more difficult to solder into turrets because of the stranded wire leads.

My gut level feeling is that I would NOT like them thru out an amp or as the primary foundation of caps being used. I am thinking about them as seasoning to the cooking (so to speak). I don't think of these as a "must have" tweak, but I do see them as useful for this specific amp and tone I want.

I'd sure be interested in the experience of others.

With respect, 10thtx

[10thTx]

OK, I did more extensive experiments today with the Musicaps.

Out of 9 caps in the signal path, 3 made a VERY significant improvement in transparency, musical tone and smoothness.

3 positions were just different. More transparent but less vowel tone. Simply a trade off. Maybe the Musicaps would be better in those positions
for rhythm and chording. But I prefer the vowel tone more of the Orange Drop PS in those positions.

3 positions were significantly negative tonally using Musicaps. Way too sterile. Very hifi-ish sounding. Transparent but no musical sweetness.

Some conclusions reviewed:

- Most dramatic results is in the first coupling cap
- IF you were going to use Musicaps, I'd try them most in the clean
channel and early OD channel coupling cap positions
- In the post LTPI, they were just different. Same was true in clean
channel tone stack.
- Certain positions they were somewhere between bad to awful
- If used in the "right" positions, you can increase the coupling cap
size for increased warmth (& maybe more sustain)

- I definitely would NOT build an entire guitar amp with Musicaps

I did find them very worth the investment in the 3 positions I used them.

With respect, Tubenit

[10thTx]

For anyone who is having some harshness or buzz in the OD channel, I might be inclined to experiment with something like this.

I am getting so much smoothness from these Musicaps in the right position that I have been able to increase the value of the cap and I have removed smoothing caps in two different positions and still have a smoother sounding amp with my D'Mars

The MusiCaps don't have a .015 value. So, I'd use a .01 value with an Orange Drop PS .0047 paralleled. I tried combining a Musicap with a paralleled Orange Drop with good results as long as the Musicap was a higher or equal value.

Anyhow, I offer this for your consideration ..............

If anyone tries this, please post your results for others.

with respect, 10thtx

[jcsifu]

I think I might be game for this. I am always after more bloom and 2nd order harmonics. I've also gotten tired of lugging a rack with D-lator and effects to gigs every time, so if it smooths my od some I could just use a reverb pedal in the loop and be good. I have been struggling with reducing my snubbers on V2a/b because to me they take the life out of the tone some but too low has brought harshness, so I have been constantly changing those values out in search of a best compromise.

Two questions:

Which position do you think will make the biggest difference in a standard ODS, the .1 feeding the bass perhaps?

What do you think the results would be if the .002 after the slope resister were to be swapped out?

[Mr. dB]

Which position do you think will make the biggest difference in a standard ODS, the .1 feeding the bass perhaps?

In hifi, caps are most audible in the direct signal path, i.e. plate coupling caps. Power supply electrolytics also have some "personality".

I would think the same rules would apply in a guitar amp, but can't speak from experience.

[10thTx]

Unfortunately, there are limited values in the Musicaps and no .002 values to my knowledge?

I think if I were going to pick 3 caps to change, it would be the .1 bass tone cap, the .047 off of V1-b plate & the first coupling cap after the V2-a plate which usually is .01 to .015.

IF I were only going to do two caps ............ maybe the .047 and the .01 in the OD?

With respect, 10thtx

[jcsifu]

Unfortunately, there are limited values in the Musicaps and no .002 values to my knowledge? 10thtx

I'm not familiar with their values, oops. Should have looked it up before I spoke.

I think if I were going to pick 3 caps to change, it would be the .1 bass tone cap, the .047 off of V1-b plate & the first coupling cap after the V2-a plate which usually is .01 to .015. 10thtx

Ok, I'll order those

IF I were only going to do two caps ............ maybe the .047 and the .01 in the OD? 10thtx

So am I understanding correctly that you would not recommend going with less than the 3 locations you suggest?


.

[jcsifu]

In hifi, caps are most audible in the direct signal path, i.e. plate coupling caps.

I agree, just wanting to glean the experience of 10thTx to hear where the earliest available swapping location would be to hear a noticeable difference.

My main curiosity would be for the OD tone but if a swap helps me like the clean sound as well, it would solve another of my on going issues for performing. I have never successfully been able to have a clean tone I like and an OD tone I like at the same time. This is to say with only using the amp with out od pedals.

[Structo]

IMHO, I think if you have a very clean amp, that some of these newer exotic caps may indeed sound good.
Like I said before, I have a couple guitars or more that have the Hovland caps in their tone circuit.
And I like them.

But, when we are dealing with an amp like the Dumble ODS amps,
I think it is better to start with what the designer's component materials were back when these amps were designed.
Try to use metal film resistors where HAD did and the same for the carbon film resistors he used in various places.
IOW, try to clone the amp and keep the same spirit of the amp.

We obviously love the Dumble ODS amps or this forum wouldn't be here.

If you trade polyester for polypropylene caps or change the ceramic caps used in certain spots, to some other medium, then I think you are going to alter the overall tone of the amp.
Unless you just want to experiment to find just the tone that is right for you.
And having a clean side as well as Overdrive like you want.

Once your amp is burnt in, it's perfectly OK to change some values on caps and resistors, to tune your amp to yourself and your guitars.
But if you like that Dumble sound, then I would stick with the types of caps and resistors he used unless they are unobtainium.

If you have checked the builds by several prominent members here, you see they went to great lengths to obtain some of the same resistors that HAD used.

My main problem was too much bass, but I know the speaker cab location in a room is very important to how it sounds.

But, I adjusted some values and my guitars sound great.

Good luck!

[jcsifu]

Thanks Tom,

I have stuck to the tried and true components as much as I can. I have never been able to find NOS resisters for the most part but I did find all values of older OD caps to use. I have tried this amp as a skyliner low plate, skyliner high plate, and just finished an HRM board and was about to change to that. I just thought maybe the hovland caps might help me out. I've done other amps before successfully but I have never been able to get my amp to sound as I hear others get with their amps. I cannot get the "chirp" at the beginning of the note. I have found pretty good note bloom though, so that makes me happy. I have not changed any values to non-dumble specs yet, maybe that is where I need to go next. I remember some cap subs that Doggears made mention of a long time back.

I have tried tube rolling, different od entrances, 124 value OD pot and trimmer. Mine is a 50 watter so I give that as part of my lacking tone. I've tried both 12L and 65 speakers and different cabs and combo cabs too. I have read every page on this forum at least 3 times since I joined and saved posts and categorized the info on them. I guess I'm getting tired of not being able to find that chirp/note attack I'm looking for. Maybe I should stop listening to Robben Ford and Larry Carlton tunes and just accept what I have.

Anyway, I'll post what results I get.

[Structo]

A lot of that is picking technique with the Dumble amps.

That chirp, is something that Robben does well.

I would love to sound like Robben but I sound like me, although I've studied his playing.

I still can't figure out how he makes his Tele sound like that.

[jcsifu]

A lot of that is picking technique with the Dumble amps.

That chirp, is something that Robben does well.

I would love to sound like Robben but I sound like me, although I've studied his playing.

I still can't figure out how he makes his Tele sound like that.

Lol,

Point taken and understood my friend. I don't do well with not getting what I want, so guess this will have to be the one that got away.

I'll play around with picking technique and so if I can get a better chirp. Maybe I have been thinking my missing component is in the amp a little more than I should.

Have a great day and thanks!

[bluesfendermanblues]

A lot of that is picking technique with the Dumble amps.

That chirp, is something that Robben does well.

I would love to sound like Robben but I sound like me, although I've studied his playing.

I still can't figure out how he makes his Tele sound like that.

Exactly right!

I built my first D clone in 2008 and it took 1-2 years to understand the the RF tone is indeed created by varying picking dynamics - on a sensitive Dumble Amp. Before the D clones I used to play fender amps with a tube screamer pedal and I never worried about picking dunamics - on the contrary I tried to pick as har as I could (on heavy strings) in order to sound like SRV on "Pride and Joy", which is the opposite of what RF is doing....he plays very soft and very soft with a hard pick. (With all due respect, when I listen to SRV these days - I hear a lot of dynamics)

Take a listen to e.g. the intro licks of "Talk to Your Daughter" or another RF tune for that matter. When you listen carefully you can hear that RF varies each and every stroke.

RF started out as a Sax player and maybe he got the attention to the details from playing the sax. Gerry Mulligan (two hard blows and one soft)) is a great example of a player who has taken blowing technique to another dimension.

You hear a lot of guitarplayers play with the same picking dynamics on all notes, but you don't hear sax players play like that.

Take this as a great opportunity to improve your playing