Where best to post about diff between Fender and Dumble?

[imo1]

Hey yall,

I'm an amateur builder, but a professional touring guitarist. I got into building after years of my techs trying to help me find the sound that was in my head. I'm an Austin guitar player that grew up with the Vaughns and EJ, and has a lot of years of experience of playing mostly Fender and Marshall circuits on stages and studios. I fell into the Dumble world because so many of his designs are Fender based, and unlike a lot of other builders, he wasn't just chasing high gain. I have learned a ton through this forum and its been very helpful to me, so thanks to many of you.

I've found, after building a number of Dumble based designs, that I love the general design, but for my type of playing, there are pieces of Fender sound that I really miss. In a perfect world, most players that are going for similar sounds as mine are mixing Dumble or Dumble style amps with Fender amps. There is a cool "funkiness" that just comes out of Fender amps that for bluesy players is so fundamental. The Dumble(SSS type) and a lot of the Two Rock stuff has so much more power in the low end, which is amazing, but kind of tend to be a bit clacky if you are using them by themselves, and I find in my own playing, that it makes a lot of that funky rhythm/lead playing (Hendrix/SRV) not work as well. I am always looking to grow and evolve as a player, but I have a defined style that is me as a player, and I'm really trying to find out how to build my amp in a way that brings that out, as opposed to me changing my playing to fit the amp.

Anyway, what I've learned is that very few serious players do much building. I think that singular focus is why the best are the best. There is a reason Derek Trucks doesn't sing, or write much. I'm trying to find that balance in my own life with building and playing. I find that I tend to go in waves, and the quality of my playing reflects that.

I would love to have a discussion about these elements in the amps, which design components work best to do what. I am looking to refine some of my amps to closer to what I'm looking for and I feel like my deep experience playing has value in these discussions, as it seems that most of the other folks on the forum are more builder focused with occasional playing.

Anyway, I thought I would post this here, both to ask the question of where in the forums it would be, and also to test the waters of is this has any value. In my mind it does to the community, but the last think I want to do is make any waves or come off as self important.

Thoughts?

Ian

[xtian]

I'm an avid live guitar player (39 gigs last year!) but don't try to earn my living that way, and I've been building for about 13 years (with vast amounts of help from this forum). I love Fender blackface amps, and Dumble amps, too. For any given song, there is the perfect amp that sags just right, at the right volume. Problem is, I play cover music, so my requirements change for every song. So I default to more powerful amps, and then get my dirt and compression from pedals.

There is no, single, magic amp that will do it all. But the chase is very fulfilling to me.

[imo1]

I definitely understand that. Though I play my own original music, I have 14 records, and have covered a lot of territory during that time.
That said, for the sound that people know me for, there is a amp, or combo of amps, to get there. I think a lot of guys have mined similar paths to mine to get that figured out.

I have a signature amp that my friend at Holy Watt is building for me. It has some elements of the Two Rock JM style. I have been trying different things to figure out what it is that I'm missing with it. I love the amp, but was missing what I was talking about above. The next thing I'm trying is a sag resistor to see if some of that power draw when i really hit a big note will get some of what I'm missing. I think after that, maybe messing some with a little less filtering, but I am worried I will lose what I love most about these designs, and thats the amazing, really well put together low end.
Its that thing i get when I play my vibrolux or super on about 6. Its just an amazing funky sound. If I could pair that with my current amp, it would be amazing, but I'm already way too loud for most situations, so trying to find a way to get closer with 1 amp. I played a show with Kenny Wayne last year, and sat in with him. I played one of his Dumble modded Fenders, and really dug that one, but he has no idea what Dumble did to the amp.

[martin manning]

Seems to me the heavily scooped Fender tone stack might be the difference? Other than that the D clean preamp is pretty similar.

[bepone]

I played a show with Kenny Wayne last year, and sat in with him. I played one of his Dumble modded Fenders, and really dug that one, but he has no idea what Dumble did to the amp.

5e3 combo? Tweedle dee?
for preffered Rhytm sounds which are between clean / crunch is better to use Marshall amps.. or from Dumble pallete Bluesmaster...

Many influence on the sound also have output transformers.. also one point to improve/change in case that something missing

[imo1]

Seems to me the heavily scooped Fender tone stack might be the difference? Other than that the D clean preamp is pretty similar.

It does seem that way. The tone stack is pretty similar to the Fender scoop style. 100k slope. .1, .047, .001 tone caps. I find that as much as a love the deep switch for certain things, I have to keep it off if I want to do any rhythm lead playing. I also have the mids pretty close to off, as well as the bass.

It's so hard to talk about tone on this level, but there is definitely a little bit of clackiness. Less top end for sure. A super has .022 for mid cap. I do really love that sound. I wish I had more time, because it would be really cool to be able to build one of these in an old chassis and be able to try all the things(get rid of the 1st stage neg feedback) experiment with less filtering, etc

[imo1]

I played a show with Kenny Wayne last year, and sat in with him. I played one of his Dumble modded Fenders, and really dug that one, but he has no idea what Dumble did to the amp.

5e3 combo? Tweedle dee?
for preffered Rhytm sounds which are between clean / crunch is better to use Marshall amps.. or from Dumble pallete Bluesmaster...

Many influence on the sound also have output transformers.. also one point to improve/change in case that something missing

I'm not sure what the amps were, but I think they were either modded bandmasters or something of that type. The best way to describe the sound, and keep in mind it was just a couple of songs a the end of a concert, but like the ultimate Fender amp. They had that amazing bite that is unique to Fenders. There is a beautiful edge that doesn't have the raspiness of a Marshall, and the notes have a legato quality to them, but again, different from the marshall compression. There is a reason so many strat players play Fender amps, and it is this sound.

In my career, I started with a Super Reverb, which I loved, but as the band grew bigger and I started writing more riffy(Hendrixy) songs, I needed a bigger tighter lowend. I spent years messing with the Super. Different cabs, ultimately rebuilding it at one point to 6550 tubes. Eventually I moved to different types of amps. I worked with Mike Zinky, being one of the first to use his Vibroking and the Tonemasters. I liked those, but I feel like Dumble's cleaner builds are the closest I have heard to what I'm going for. I may mess with the Euphonix mods at some point, but I have so many amps right now that I am reticent to build any more.

[WhopperPlate]

I suppose I will be the person to answer the posted question:

“Where to best post about diff between Fender and Dumble?”

Answer:

The Dumble sub forum of the ampgarage…nudge nudge

I've found, after building a number of Dumble based designs, that I love the general design, but for my type of playing, there are pieces of Fender sound that I really miss. In a perfect world, most players that are going for similar sounds as mine are mixing Dumble or Dumble style amps with Fender amps. There is a cool "funkiness" that just comes out of Fender amps that for bluesy players is so fundamental. The Dumble(SSS type) and a lot of the Two Rock stuff has so much more power in the low end, which is amazing, but kind of tend to be a bit clacky if you are using them by themselves, and I find in my own playing, that it makes a lot of that funky rhythm/lead playing (Hendrix/SRV) not work as well.

Thoughts?

Ian

I have the opinion that most cloned circuits out there generally either have too much clack and quack , or too little. The temperamental nature of the whole recipe demands careful adjustment, and if you aren’t careful you can over compensate with band aid circuit value adjustments. A lot of this boils down to component materials and their inherent characteristics, and when you use the typical cathode bypass values of 5uf across the board through the preamp this really becomes sketchy. Easy way to smear and blur that line is to raise those values back up to fender territory , definitely will tame the clack and return some “cool funkiness” .

Another thing is the typical 820R 24k LTPI compresses and evens the response of the power amp unfavorably for a classic feeling response imo. The earlier generation amps, the ones that don’t get cloned as much , often have that classic fender values 470R 22k and that is another wide turn back into “cool funkiness”

[imo1]

If the moderators wanted to move it.

I didn’t know if the topic would fit in the dumble threads. To me, as a player, I’m interested in using dumbles design platform as a solid foundation to find what works for my playing, and I think that my journey parallels that of many other players too. The fact that I know enough to have fundamental understanding of the blocks that make up these amp circuits has helped me get a lot closer than I could in 20 years of working with some of the best techs and builders in the business.

I definitely am interested in exploring all of these thing!

[martin manning]

I wish I had more time, because it would be really cool to be able to build one of these in an old chassis and be able to try all the things (get rid of the 1st stage neg feedback) experiment with less filtering, etc.

Some things are easy to try in a non-invasive, non labor-intensive way, for example you can defeat the LNFB by grounding it out. It's a bit more work to play with filtering, but not too much, lifting a lead and clipping in parts. I think a very interesting experiment would be swapping out the Dumble tone stack for a straight-up Fender to see what is lost or gained. That could be done by building a Fender tone stack in a pedal enclosure, disconnecting at the V1 plate and the volume pot in the amp, and clipping the Fender in. Dumble was obviously pretty proud of the Skyliner, hiding the details under silicone and all.

[imo1]

Hey! I really appreciate everyone's responses. I know you guys all have a good deal of experience, and your viewpoints and suggestions are really cool.
One of the things that I referred to in the first post was the balance between guitar playing and building. I am trying to focus most of my time on playing over the next week(big gig with an idol of mine next week) and I didn't want that to interfere with the momentum of building this thought. For me, truly playing, with joy, in the studio, is an essential part of me getting "better" as a guitar player. I think it can serve some thoughts towards this because I am going back and forth between one of my 100w builds based on the Two Rock JM, and a couple of my Fender amps. It's really cool to be able to spend hours with both. I find that when I test them and only spend a few minutes I really get a cursory opinion about them. The value is when I start playing and get to the nuance that my brain recognizes in how the notes are responding; that is how i can get to the level of the amp really being a fine tuned workhorse.

I'm excited to try some of these--
Tonestack--I'll have some more questions on this. I do see the .001 treble cap is different.. Wouldn't it be easier to just sub in a 250p.. I'm assuming the rest of the stuff(bright switch, mid switch, and deep) shouldn't have any affect on the circuit if not switched in.

Neg feedback- yeah. I like having that on a switch anyway(do on my other build) I actually prefer that first stage without it, at least I have when trying it at soundcheck/ Again, want to really take time to truly hear it and understand how it affects feel/

-cathode cap variation-- I would be curious to hear more thoughts on this. I theoretically know what cathode caps do, and I understand how they can shape sound with highpass based on value, but I don't truly KNOW what that sound difference is yet, so I'm not able to visualize how this would actually impact the sound.

-Power supply caps--On this amp, build in a Ceriatone board, the power supply uses axial caps, so it's much more difficult to get into. Once i get another 50W going for my touring, I'm going to ship the other 100W from my gear location home(I tour out of a different state, so half of my gear lives 2000 miles away), built on the amp nation layout, and that will make it easier for me to go back and forth to hear differences.

-Leaddress/layout- I definitely understand fundamentally how to do this and what it means. I guess the one area where my spidey sense goes up is when people talk about leaddress with trying to get capacitance and resistance in a tuned manner. I did an AES keynote a few years ago and the presenter after me(Eric Valentine--brilliant!) did his speech on quantitatively proving that aural testing is a flawed methodoogy. I know a lot of builders of high end studio audio(mostly vintage varietals) and though they definitely value high quality components and understand material types for resistors and capacitors, they really seem to understand a level of audio tuning that is much more practical. /my opinions on resistor and cap brands(within composition types) are that this is mostly a non factor, and the only real consideration would be quality of components(such as ESR for caps). To that regard, this is where I wonder if Dumble was a putting a little bit of pretend fairy dust on things. I just think if you are talking about a touring rig, unless you are bundling unlike cables together with some awareness that I haven't yet seen or heard, I need some true convincing.

[martin manning]

Tonestack--I'll have some more questions on this. I do see the .001 treble cap is different.. Wouldn't it be easier to just sub in a 250p.. I'm assuming the rest of the stuff(bright switch, mid switch, and deep) shouldn't have any affect on the circuit if not switched in.

Correct, and yes, subbing in components is relatively easy, especially so if you can get the change you want to try by paralleling. Not sure what you are referring to by a "0.001 treble cap." The Skyline stack has 300-390p going into the top of the treble pot vs. Fender's 250p (Skyline is more mid-biased), and that could be something to try. I think maybe increasing the mid cap (10n) in the Skyline stack would be most revealing, as that will restore the mid scoop. Try paralleling a 22n in to give that a try. With those two changes, plus shorting the bottom of the bass pot to the top of the middle, you'd be very close to the Fender AB763 EQ.

I theoretically know what cathode caps do, and I understand how they can shape sound with highpass based on value, but I don't truly KNOW what that sound difference is yet, so I'm not able to visualize how this would actually impact the sound.

Another place where you can parallel caps to see what filling in the low bass sounds like.

I did an AES keynote a few years ago and the presenter after me (Eric Valentine--brilliant!) did his speech on quantitatively proving that aural testing is a flawed methodoogy. I know a lot of builders of high end studio audio (mostly vintage varietals) and though they definitely value high quality components and understand material types for resistors and capacitors, they really seem to understand a level of audio tuning that is much more practical. /my opinions on resistor and cap brands (within composition types) are that this is mostly a non factor, and the only real consideration would be quality of components (such as ESR for caps).

I'm with you all the way there! I believe there are a lot of people out there chasing red herrings ;^) I'd be very interested to know how presenter Valentine went about proving his claim.

To that regard, this is where I wonder if Dumble was a putting a little bit of pretend fairy dust on things. I just think if you are talking about a touring rig, unless you are bundling unlike cables together with some awareness that I haven't yet seen or heard, I need some true convincing.

HAD was known to have a sense of humor, and was not above being deliberately vague or even pulling a few legs, IMO.

[martin manning]

Another thing is the typical 820R 24k LTPI compresses and evens the response of the power amp unfavorably for a classic feeling response imo. The earlier generation amps, the ones that don’t get cloned as much , often have that classic fender values 470R 22k and that is another wide turn back into “cool funkiness”

The 470 ohm bias resistor generally goes with a 12AT7 PI, and the 820 ohm goes with a 12AX7/7025.

[WhopperPlate]

Another thing is the typical 820R 24k LTPI compresses and evens the response of the power amp unfavorably for a classic feeling response imo. The earlier generation amps, the ones that don’t get cloned as much , often have that classic fender values 470R 22k and that is another wide turn back into “cool funkiness”

The 470 ohm bias resistor generally goes with a 12AT7 PI, and the 820 ohm goes with a 12AX7/7025.

Merlin Blencowe has a good write up on this in his books . I took some photos for a different thread discussing the same aspects . You can see how 820 is inevitably more symmetrical, even with a ecc83

[imo1]

Martin. My tone stack is actually taken from the Two Rock, which is .1, 047, and .001. Since, aside from the treble cap, this is similar to most of my Fenders, that is an easy sub to check.
I normally put in the feedback defeat switch for that first stage, and generally have preferred that, though I would like to spend more time really listening to each.

One of the biggest things that I love about Fender style amps is the pull when you hit a note hard and bend it, and the amp seems to "bend" in a way. I find this to be one of the most emotional things and for me, the best players, or at least the most subtle and emotional players, have this at the core of their playing. I am a huge Hendrix fan, and have a bunch of Marshalls, but I've always found them to be less "soulful" amps in terms of nuance of emotion. To me, I think the thing I am responding to is probably the sag of the power supply. I am going to try putting a sag resistor after the rectifiers to see how much of that I get from the amp. Ive read a good deal about valve rectifiers and their behaviour with voltage demands. Supposedly if you nail the right amount of sag with the correct resistor for the rectifier type, its hard to tell the difference.