Stephen1966 wrote: ↑Mon Sep 11, 2023 7:07 pm
My own thoughts are that this could be because there were no specific dimensioned chassis available at the time and MrD needed something of very specific dimensions (perhaps for a cab he was working with), but then... why did he repeat it, with #183 for example?
What are your thoughts?
I think there were perhaps a few reasons:
- Durability - these chassis are STRONG
- Keep the entire process under his control
- Cost - once set up they are really inexpensive compared to a large run from a metal shop
- Serviceability - the modular design allows you access that other chassis do not. I have already done work by removing the side and front panels - super easy
Regarding the size, I think he still stuck to a standard size (although the one I worked on was slightly smaller in length). From what I can tell and from others that have been inside other amps, the dimensions are pretty consistent.
I think this makes for a more compelling set of pragmatic reasons than the idea he was building it to fit a cab! Is it correct to say that MrD farmed out the chassis work and silkscreening for some of his amps? I genuinely don't know, so I'm asking. But I can easily imagine that for whatever circumstances there was a time when his "normal" supplier was not around and so with characteristic resourcefulness, he decided to make his own. I think of all the reasons you mention though, keeping the process under his control is by far the most compelling.
With MrD it seems more likely than not, that what we see is often the result of a confluence of reasons. Perhaps the problem is that I am looking at this too near-sightedly, looking for a single compelling motivation or reason to explain the decisions he made. It's tempting to try and rationalise his process (for ourselves) that way and tempting to think that there has to be any concrete rationale. You know, sometimes it just "makes sense" to put the thing together that way. No particular reason, you know? Just a bunch of ... advantages, to doing it this way. I will be the first to confess, I'm too obsessed with data. I never really bought the idea he made the chassis to fit a cab, it seems too accidental, and of everything of his I've seen or thought about, I don't recall seeing anything at all that we could call "accidental".
Thanks Ian, you bring real insight to the conversation.
timrobertson100 wrote: ↑Sun Jul 30, 2023 3:28 am
Beautiful work. How did you do the white lettering please, Ian? It has come out very sharp.
Thank you. I have a vinyl cutter and it does a great job. Sprayed with black gloss Krylon, applied lettering and then hit it with Krylon clear gloss. As I learned, make sure to leave at least 24 hrs. between coats. 3 failed attempts later and I finally learned the art of patience....
Hi Ian, what a fantastic build! You really know what you are doing! I am really impressed by your chassis build. I think the vinyl lettering works really well with this chassis. I take it that HAD silk screened his lettering .....or are you going to tell me that he used a vinyl cutter!!!!
Would you mind telling me what brand are the coupling caps? I get the impression you are a strat player. How does the amp sound with hum buckers?
Once again, stunning build.
ATB.
Andy
Dr d wrote: ↑Sat Mar 30, 2024 7:47 pm
Hi Ian, what a fantastic build! You really know what you are doing! I am really impressed by your chassis build. I think the vinyl lettering works really well with this chassis. I take it that HAD silk screened his lettering .....or are you going to tell me that he used a vinyl cutter!!!!
Would you mind telling me what brand are the coupling caps? I get the impression you are a strat player. How does the amp sound with hum buckers?
Once again, stunning build.
ATB.
Andy
Thanks Andy, I really appreciate the kind words. I have no idea what HAD used but I have heard silkscreen mentioned and that sounds about right.
The coupling caps are all NTE Mylar 630V except for the cap on the bass pot which is an SBE 715P. I used to play strats exclusively but since going down the Dumble path I have been playing more Les Paul's or ES-335s. Strats are so hard to get right with an ODS. I heard that HAD used to use a strat when building his amps, theory being that if he could get it to sound good with a strat it would kill with a Les Paul.
Dr d wrote: ↑Sat Mar 30, 2024 7:47 pm
Hi Ian, what a fantastic build! You really know what you are doing! I am really impressed by your chassis build. I think the vinyl lettering works really well with this chassis. I take it that HAD silk screened his lettering .....or are you going to tell me that he used a vinyl cutter!!!!
Would you mind telling me what brand are the coupling caps? I get the impression you are a strat player. How does the amp sound with hum buckers?
Once again, stunning build.
ATB.
Andy
Thanks Andy, I really appreciate the kind words. I have no idea what HAD used but I have heard silkscreen mentioned and that sounds about right.
The coupling caps are all NTE Mylar 630V except for the cap on the bass pot which is an SBE 715P. I used to play strats exclusively but since going down the Dumble path I have been playing more Les Paul's or ES-335s. Strats are so hard to get right with an ODS. I heard that HAD used to use a strat when building his amps, theory being that if he could get it to sound good with a strat it would kill with a Les Paul.
Hi again Ian,
Yes, I think he probably silk screened the panels. I'm trying to guess what else he might have had available to him other than, say, letraset.
So, are the front and back panels essentially preformed (cast?) U section aluminium bought to length? Also, I know you are convince that this construction has a beneficial effect on the overall performance of the amp.....is this due to the way it is constructed, grounding scheme, the thickness of the aluminium, or all?!
Finally (?), I have no experience with the NTE Mylars. How do they compare to the typical 6PSs that HAD used in tone?
As always, I really appreciate your response.
ATB,
Andy.
Btw, I totally agree with your comment regarding strats. I love them, but getting them to sound good through an ODS is challenging. Makes perfect sense that HAD would tune an amp with a strat.
Dr d wrote: ↑Sun Mar 31, 2024 8:40 am
Hi again Ian,
Yes, I think he probably silk screened the panels. I'm trying to guess what else he might have had available to him other than, say, letraset.
So, are the front and back panels essentially preformed (cast?) U section aluminium bought to length? Also, I know you are convince that this construction has a beneficial effect on the overall performance of the amp.....is this due to the way it is constructed, grounding scheme, the thickness of the aluminium, or all?!
Finally (?), I have no experience with the NTE Mylars. How do they compare to the typical 6PSs that HAD used in tone?
As always, I really appreciate your response.
ATB,
Andy.
Btw, I totally agree with your comment regarding strats. I love them, but getting them to sound good through an ODS is challenging. Makes perfect sense that HAD would tune an amp with a strat.
Hey Andy,
The panels are C-channel 1/8 inch aluminium that I trimmed the top and bottom lip. I'm not entirely sure why or what this does to the overall tone. I suspect it is the thickness and quality of the Aluminium that creates good ground pathways through the chassis.
The NTE Mylars to my ears are a little less bassy and have a clear sweet top-end. I have seen HAD use them in other amps where it would be all or in some instances he would add a few to taste (#0183). Whatever the formula this amp is by far my favorite with the #183 a close second.
Dr d wrote: ↑Sun Mar 31, 2024 5:35 pm
Thats useful to know, thank you. So where does the 3rd gen build figure?!
If I were to cover the most ground I would take the HP Skyline and 3rd Gen. Totally different amps but do their own thing really well. The 3rd Gen is great for strat cleans and does great ZZ Top with the LP.
Dr d wrote: ↑Mon Apr 01, 2024 7:35 am
Hi Ian, so i've picked up on the el34s. I'm guessing this might have a high B+. Don't worry if you don't want to answer this one.
Hey Andy,
The B+ is around 460V with the bias at 60% for the HP skyline and the Dumble. Same for the #0183
Last edited by ijedouglas on Mon Apr 01, 2024 2:08 pm, edited 2 times in total.
Dr d wrote: ↑Mon Apr 01, 2024 2:05 pm
Thanks for your reply Ian. The amp seems in many respects to be a forerunner for #183. Very intriguing!
Yes, the Dumble had an interesting power supply and pot tapers. They were very similar to a bluesmaster. The PS dropping string is 6K=>15K=>10K and the pot tapers were all 10%. I'm guessing the amp started out as a bluesmaster and was converted around 2005 by HAD to a skyline.
That first resistor in the dropping string surprised me. It’s what made me wonder if it had a particularly high B+. Very interesting amp……and you have confirmed it sounds good too! Tempted to convert a Bluesmaster build of mine into something similar.
Dr d wrote: ↑Mon Apr 01, 2024 3:04 pm
That first resistor in the dropping string surprised me. It’s what made me wonder if it had a particularly high B+. Very interesting amp……and you have confirmed it sounds good too! Tempted to convert a Bluesmaster build of mine into something similar.
It's my favorite build so far. I have a good friend, who has played over 40 Dumble's, try it out and he absolutely loves it and said it sounds just like the Tan Ultrasound amp
