First Poster on my TW Express build

[chrisq206]

So with some finishing help with my man Brent Bagby at Solderhaus, I completed my first TW Build, an Express.

Went with Pacific Iron, Roedrestien/Vishay sp? (German polyester) caps, mostly Takman resistors, F&T can caps, mostly NTE 22 solid core wire (except where I needed something bigger)

l'll post a pic soon.

Sounds great as far as I can tell. different than other amps I own and have played, which is quite a few. Very dynamic, lots of sound, comes out, tons of sustain at full wack. Touch sensitive (that's no joke).

This in the only TW type amp I've ever played, so I have no idea how it stacks up against others. Standing in the room with my amp sounds better than all of the clips I've heard, not because I think mine's better, clips just have a huge disadvantage over a live amp.

So here are some observations to comment on.

Anything other than single note playing (which sounds amazing) at full up doesn't sound so hot to my ear. a bit spitty as they say. I'm guessing that's normal considering the amount of gain? Not to my taste anyway. Great sweet spots when backed off though.

I think I prefer the NOS RCA 12AT7 in the PI. It seems to sound a little more focused that way. right now all of the pre tubes are NOS

It seems to Like the set of JJ E34Ls over the EH EL34s, although the JJs are biased a little cold at 36ma because I haven't changed the resistor to get it up higher from when the EHs were in there. Any preferred bias.

I've been running it through a Marshall reissue cab with broken in Greenbacks.

I tried some Eminence Swamp things which sounded good and tamed the amp a bit which might come in handy, but didn't have the excitement of the Greenbacks. didn't love the way it sounded through the Fanes in my old Hiwatt Cabinet.

Haven't played it with my band, or recorded with it yet. It will kill in the studio though, that I can tell.

Any constructive thoughts or input would be appreciated.

[RJ Guitars]

Chris,

that sounds like a good report... can you get us some photos?

thanks,

rj

[chrisq206]

Here are the shots. in addition to the above info, I used and old style Marshall type phenolic board that I drilled for turrets. I thought the tubular style 25w resistor seemed cooler than the regular cement ones.

Enjoy!

[chrisq206]

RJ

If you get around to commenting. Whats the word on Edcore Transformers for Rockets and Expresses vs. Pacific? They look nice and the price is right.

[chrisq206]

RJ

If you get around to commenting. Whats the word on Edcore Transformers for Rockets and Expresses vs. Pacific? They look nice and the price is right.

[JoeCon]

Chris
Really nice build. I like the can caps a lot really simplifies the circuit inside.
I used Edcors in Rocket and Rockster build and both sound nice. But I have not tried the "others" so I can only tell you about the Edcors...

[gktamps]

I've now used Edcor, Pacific and Heyboer OTs in Rocket type amps, including an 18 watt version. Pacific is a little darker, but really toneful and great cleans and grit when needed. Heyboer a bit brighter, does the job well.

Have to say I didn't end up liking the Edcor - too much edgy distortion for my tastes. Edcor was quite a bit less expensive, but the time and materials cost to build a nice amp made the price difference insignificant to me.

https://tubeamparchive.com/viewtopic.ph ... 873#304873

[JoeCon]

Greg

I'll try a Pacific in my next Rocket sounds like it would be good foil to the Edcor one.

Thanks...

[RJ Guitars]

RJ

If you get around to commenting. Whats the word on Edcore Transformers for Rockets and Expresses vs. Pacific? They look nice and the price is right.

It takes a combination of science and experimentation as well as the preference of your own ears to sort out which one works best.

For the Rocket, most folks agree with Greg that the Edcor is what I call a little "sterile" in the Rocket build. Other folks just refer to them as "simple" sounding. The price on them is great and it is a good tranny for some folks and some builds. The Rocket circuit really lends itself to to a complex array of tones and harmonics and I'll suggest the Pacific and other Dynaco style trannies are better for getting all the sound out of that amp.

For a 15 watt Liverpool I have an Edcor OT that sounds amazing and is very affordable... so it's not just about size and price. I'm working with Pacific to develop a tranny for this amp with them, but I don't have any disappointment with Edcor here.

In the Express, I think the Edcor goes well with the 6V6gt tubes especially on the 5.2K tap. But historically the best sounding Express amps usually have either a Stancor, Pacific, or some versions of the Heyboer and a 6.6K tap.

They Edcor trannies were developed as HiFi trannies and it's actually kinda funny to talk with their engineer about pushing the transformer into distortion... he knows that is important to guitar amp technology but not entirely intuitive from the HiFi perspective. In a guitar amp they tend to work well for a simple uncolored tone... except that 15 watt unit which I can't really explain.

As far as power transformers go I think I like the Edcor units better than the other manufacturers because they are very finicky about Quality control. I've sold hundreds of them and have only seen two bad ones overall... which they cheerfully replaced. I've never had one get hot on me and they look great.

So, there are trends but there is still an element of personal preference. If you want to develop a new amp you might start with Edcors then to get the ultimate tone consider a Mercury Magnetics once you've worked the bugs out otherwise.

[JoeCon]

Interesting about the Rocket: if the Dynaco is the xformer used wasn't it a Hi-Fi unit?? And the Edcors are also a Hi-Fi unit?? Is it the construction of the xformer that's different?

And while we are on the subject I have another xformer question:how come a 3K for the Marshall 1987 2 x EL34 but the Express, same output tubes, uses a 6K??

Thanks!!

[M Fowler]

Nice looking build but needs the Davies knobs

Edcor transformers are very good and I like the darker flavor they provide whether I'm building Rockets with EL34 or EL84 power section versions.

Pacifics sound great as well in Express and Rockets haven't tried a Liverpool with Pacific yet, I used Heyboer.

Heyboer have been hit and miss for hum in the PT's for me.

I use the Dynaco type 4k3 OT in many different types of amps Rocket, Dr Z's, and even Marshall JCM800 50w.

[JoeCon]

Mark

Have you used the Triode Dynaco reissue??

[M Fowler]

Mark

Have you used the Triode Dynaco reissue??

Yes many times for both TW Rocket, Zwreck and Marshall 50w

[chrisq206]

Thanks RJ for the thoughtful responses on the Trannsformer questions.

Surprisingly, no one has mentioned Mercury.

Pacific seems to be the general preference, which is good and bad for me. I used Pacific in mine and I'm pleased as far as I can tell, but as a tinkerer, I always want better. I guess that's the problem with starting at the top.

I ordered my Pacifics from Pacific. I didn't know about RJ at the time. Are the TW transformers ordered direct from Pacific different from RJ Pacifics?

[Colossal]

Surprisingly, no one has mentioned Mercury.

I have used Mercury's A-470-S for a Rocket and it sounds excellent.