Wire

[Richie]

Color of wire in the heathers, also the fact that the heathers are wired in phase. If you look at Francesca's heather wiring goes out of phase from v1 to v2 (inverted) and then is inverted again from v3 to v4 to recover phase...strange...isn't it?

Not too strange,other amps have used this method before. There were a few amps we have seen where a few tricks were used,and it does smooth out the top, and cure parasitics, also helps pic tubes to use in the preamp a bit better. But, the trick seems to be,without any tricks

Now if you change things, you can make it different, thicken it up smooth the top end etc. But again,trying to use the same thing,and make it sound right. Even Ken himself had amps that just didn't come out right. Some may be a bit better sounding. Its like trying to unlock a combination lock, you may have 2 of the numbers, but it won't open till you figure out the last one.

Glen, yes he used those pots and others,or a mix in some amps, or that is what is shown in some pics..
Those were made for board mounting,kind of like early PC mounted pots.


No lug,just wrap around the leg of the pot, other amps use those too old Ampegs for one.. he used some other 2 watt pots too. Seems he didn't like those after they moved the manufacturing to mexico. the early USA ones he liked. Which you can still find those.

[funkmeblue]

I remember reading that the owner of the undocumented express aka reject 90 replaced the input jack and added the grid stopper to fix a problem with this amp. Was supposely built for eric johnson but was rejected.

[Structo]

Glen I'm wondering if your amp is a bit less harsh sounding due to the older caps?

That and other components that drift and change with age.

For example, we know power tubes generally lose some high end sparkle as they age.
But it happens so slowly that we don't notice it too much and usually compensate with the tone controls when setting up.

So how about film caps, CC resistors, transformers.

I wonder if the metallurgy of the transformer laminations changes over time from the bombarding of the magnetic flux on them?

Many of you probably saw the thread in the Dumble section where we discussed whether or not Mr. Dumble could clone one of his own amps and have it perform exactly the same as the original in tone and feel.

I think the general consensus was probably not. Too many variables that can't be controlled. Maybe if given enough time he could make it very close.

I got turned onto the Teflon wire over in the D section a few years back.
It seems like a lot of the guys there like it.
It's kind of nice to have a small diameter wire on a more complex amp because there is so much of it.
I know stripping it is a pain but having a tiny wire that is rated at 600v is pretty cool.

I have heard the harsh tone criticism before about it and I guess the only way to test that theory would be to have two ODS type amps with the same components and build one with 20ga PVC 600v wire and the other with the 20ga Teflon. (use 18ga on the heaters)
I think on the ODS amps, there are a few places where the harsh tones are addressed electronically, so maybe that takes care of most of the harshness that the wire theoretically produces.

Like I mentioned, the main attraction to me is the ability to withstand high temperatures.
Especially with the Teflon shielded cable.
No melting of the inner jacket when soldering.

[Cliff Schecht]

Special wire strippers are required for Teflon wire. If you don't have them then stripping your Teflon wire will be a nightmare. The set of strippers I use are at least 30 years old but I use them for all wire types.

Also, as I recall, R.G. mentioned over at DIYStompboxes that he uses a $40 set of thermal strippers to do his Teflon wire. I can't vouch for these though, I've never used one.

[Richie]

One of the interesting things about metals used in OTs is that distortion characteristics increase with "jarring" of the transformer. Literally, if you hit your OT with a hammer, it will distort more.

Well just ship the amp across country and back by UPS, you would have a death metal amp by then , well maybe the only thing left would be the transformers,the rest would be pieces.
Alot of people like the old iron much better,just something different about the metal i guess.

now we will see the 4 and 5 hammer tap mod

[UR12]

I can't believe you guys haven't gotten into discussing the merrits of using real rubber feet instead of those harder plastic ones

[dartanion]

I can't believe you guys haven't gotten into discussing the merrits of using real rubber feet instead of those harder plastic ones

What about those high buck pointy brass feet that the audiophools use

I think a hammer mod could be the ultimate in tuning an amp. If at first you don't get your tone, try a bigger hammer! Or a few more whacks

[Structo]

Hehehehe, yeah the urban myths abound about our favorite amp builders.

Ken and Alexander Dumble would have made an interesting pair.

I wonder how much fun Ken was having at our expense when he said things in interviews or in magazines (Trainwreck Pages).

I am not a connoisseur of Trainwreck amps although I hope to build a Rocket some day.
But looking at some of his work with hobbyist eyes, I wonder about his choice of things and his general build practices.

Now don't get me wrong, I understand how cool these amps are but the first time I saw a gut shot of an Express amp, I was like wow, so that is a Trainwreck? The layout and build execution just doesn't look that great to me.
From the looping heater wires to the Cap Stack, it looks more like a shade tree tech built amp then a super knowledgable amp guy like I know Ken to have been.

Don't TAZE me bro!

So when I read that he said certain red insulation sounds better than other red insulation, I really have to wonder if Kenny was having a good time at our expense.

[rawnster]

Hehehehe, yeah the urban myths abound about our favorite amp builders.

Ken and Alexander Dumble would have made an interesting pair.

I wonder how much fun Ken was having at our expense when he said things in interviews or in magazines (Trainwreck Pages).

I am not a connoisseur of Trainwreck amps although I hope to build a Rocket some day.
But looking at some of his work with hobbyist eyes, I wonder about his choice of things and his general build practices.

Now don't get me wrong, I understand how cool these amps are but the first time I saw a gut shot of an Express amp, I was like wow, so that is a Trainwreck? The layout and build execution just doesn't look that great to me.
From the looping heater wires to the Cap Stack, it looks more like a shade tree tech built amp then a super knowledgable amp guy like I know Ken to have been.

Don't TAZE me bro!

So when I read that he said certain red insulation sounds better than other red insulation, I really have to wonder if Kenny was having a good time at our expense.

I think you've strayed too far from home. Better head back to the dumble forum before some trainwreck builders pull up with the black van!

And yeah, teflon wire sucks!

[Aurora]

Hope you don't mind me hanging on to this for one more post, - but I've been looking and reading these topics for a couple of years now, from an EE POV...and as with HiFi and the Audiophool camp, there are several things I have some problems with. Audio myths are one thing, but on another forum where I operate, a thread about the audibility of speaker cables have now passed 1200 pages and 12000 posts! As usual the arguments fly back and forth from one camp to the other about why some people hear what they claim and why the other camp can't measure what the others hear......
I guess the only way is to agree that at some points we disagree...

As for teflon , it's main advantage is as you all know the resistance to heat is one of the best I know of, so even if it is a PITA in some cases, it's still has it's good uses. I do, however, find it hard so believe that the cable itself "sounds" different , - there must be a logical explanation. Capacitance variations is my closest bet, although untested, - inductance in these small pieces of wire... no way!

EDIT: There is a very good example of the myths from the Audiophile community, where most of the boutique manufacturers will stuff their amplifiers with all sorts of "mystical parts" , like resistors and capacitors with all sorts of strange abilities , by claim, and then of course the price just gets close to hilarious. Another manufacturer, Pass Labs, by Nelson Pass, who is himself a sort of a myth in the HiFi world, more or less says all this is just BS, but advocates the good use general components albeit of high industrial quality, as well as a very high build quality. Pass Labs generally generally get highly praised, close to raving, by the reviewers and is more or less in it's own league....

[FYL]

As usual the arguments fly back and forth from one camp to the other about why some people hear what they claim and why the other camp can't measure what the others hear......

Believe, not hear. All reliable listening tests - ie. double blind or similar - demonstrate that there are strictly *no* subjective differences between properly designed, built, chosen and used components. And if there's a perceptible difference, basic science explains why and how.

[Structo]

Hey Ron,

I kid! I kid!

I see a big bottle Rocket in my future!

[rawnster]

Hey Ron,

I kid! I kid!

I see a big bottle Rocket in my future!

Yeah. See how nice the wreckies are. If someone tried to "kid" about dumbles in the dumble forum, they would have gotten flamed to a charbroil! I know; I still have scars from funk.

[Jana]

White wire with different colored magic markers works for me. Never had an electron complain yet.

Now where did I put my tinfoil hat? Ah, here it is, right next to my voodoo doll and salt shaker.

Jana -->running and ducking for cover!

[gearhead]

re strictly *no* subjective differences between properly designed, built, chosen and used components.

The problem is that they are not all properly (or uniformly) designed, built, chosen, and used. Hence folks preferences.

And if there's a perceptible difference, basic science explains why and how.

Agree that basic science -could- explain perceptible differences, but you gotta know what to look for to be able to apply basic science. For instance, under the influence of an external EM field, do same-value components with different composition react differently?