David Bray, Metro amp mod sound clip

45auto · Post by **45auto** » Mon Oct 02, 2006 5:19 pm

Mark, didn't you build a 100watt with a 4th preamp tube? How did that sound? I forgot you've been working on a T-wreck lately right? That's what I'd like to try. When are you going to posts some clips of your lady? i love the "bray" mod sound, but couldn't this type of sound be achieved by cascading the inputs & a few component changes, modding the tube voltages & such? do the bray heads keep the stock bright & normal channels? are there any added push-pull pots or such?

wdelaney72 · Post by **wdelaney72** » Tue Oct 03, 2006 9:15 am

rockstah wrote:bah!

+1

Swissross,
I'm not busting on you, I just can't stand these clowns who tweak something that they didn't even design in the first place and act as if they've invented electricity.

robert · Post by **robert** » Tue Oct 03, 2006 9:27 am

Hi wdelaney 72,

absolutely ++1!

Regards

Robert

45auto · Post by **45auto** » Wed Oct 11, 2006 11:31 am

i pm'd gnugear about the bray mod he removed from his '74, but he must not want to reveal what he saw. i guess i can respect that... waaa....

Bluesgeetar · Post by **Bluesgeetar** » Mon Oct 16, 2006 8:46 pm

Swissross, Not trying to bust on you either but why don't you also send some money over to the Marshall head quarters in England since it is their amp design. Oh and send some money over to Fender for inventing the Bassman circuit that it all is based on. Oh and shoot Blatz some cash for that wonderful layout you referenced. Oh and George for this forum that provided you with the info to build the Plexi.

No offense bro but you are full of it. AS far as I am concerned this is a piece of spam on this forum for Bray. This forum to me has always been about sharing ideas and tweaks and helping each other with each others Marshalls to achieve the sound we want. You on the other hand are spamming for Bray. If you are not going to share the piece of info then don't post. Or post this in the "off topic" section. Cause that is what this is, "off topic". It's as useless as what is your favorite Simpsons episode to why hot dogs come packs of 10 and buns in 8.

Although I am curious as to why hot dogs come packs of 10 and buns in 8?

Brentsp · Post by **Brentsp** » Sat Oct 21, 2006 7:02 pm

Heres some chassis shots of a Bray modded 73 Marshall.

http://forum.metroamp.com/viewtopic.php?p=76870#76870

swissross · Post by **swissross** » Sun Oct 22, 2006 4:13 pm

Bluesgeetar wrote:Swissross, Not trying to bust on you either but why don't you also send some money over to the Marshall head quarters in England since it is their amp design. Oh and send some money over to Fender for inventing the Bassman circuit that it all is based on. Oh and shoot Blatz some cash for that wonderful layout you referenced. Oh and George for this forum that provided you with the info to build the Plexi.

No offense bro but you are full of it. AS far as I am concerned this is a piece of spam on this forum for Bray. This forum to me has always been about sharing ideas and tweaks and helping each other with each others Marshalls to achieve the sound we want. You on the other hand are spamming for Bray. If you are not going to share the piece of info then don't post. Or post this in the "off topic" section. Cause that is what this is, "off topic". It's as useless as what is your favorite Simpsons episode to why hot dogs come packs of 10 and buns in 8.

Although I am curious as to why hot dogs come packs of 10 and buns in 8?

Why don't you stomp around and cry a little more. That's gotta be one of the most worthless posts on these boards. Offense taken

rockstah · Post by **rockstah** » Sun Oct 22, 2006 4:16 pm

xenrelic · Post by **xenrelic** » Thu Mar 01, 2012 4:40 am

Here's a Bray 1987x Rework 1:

http://img854.imageshack.us/img854/2174/dscf0045k.jpg" onclick="window.open(this.href);return false;
http://img141.imageshack.us/img141/4338/dscf0047d.jpg" onclick="window.open(this.href);return false;
http://img851.imageshack.us/img851/5869/dscf0054a.jpg" onclick="window.open(this.href);return false;
http://img685.imageshack.us/img685/1786/dscf0053z.jpg" onclick="window.open(this.href);return false;

Sorry about the crappy cell phone pics.

PPIMV:
.1uF caps from P.I. plates to dual 500K pot.
1uF caps from dual 500k to 470k bias feed resistors.

The cathode resistor and bypass cap on V1 are a .33uF/820R parallel circuit and another cap of unknown value in series with a 5.6k/.047uF with a wire between them to a push pull switch to ground, the other side of the 5.6k/.047uf parallel circuit has a wire attached to a foot-switch jack that is engaged via an SPST foot-switch to ground.

The amp sounded like garbage to me when I got it and needed a lot of work before it was playable to my ears.

1st off, the Svetlana 34s needed to go. JJ's were installed right away and biased @ 60% plate dissipation and this was a huge improvement off the bat but the amp was still kind of sterile sounding and the gain wasn't really that fantastic.

Sounded way better after I swapped those cheap mylar caps out with Sozo mustards and I also ended up changing the cathode cap values.

The crappy resonance circuit (which didn't really do much) just made the amp sound even worse, so it was removed and I replaced it with a 47k NFB resistor to the 8ohm tap and a switch that changed the NFB to 100k on the 4 ohm tap for different tones. 27k on the 16ohm tap was good sounding too.

I swapped the preamp filter to a dual 32uf JJ cap.

Internally jumped the channels and she was good to go!

Much better tone after those changes. Especially after the Sozo caps broke in.

TJB · Post by **TJB** » Thu Jan 31, 2013 6:56 pm

So just to be clear your saying on the Bray PPIMV (2) .1uf and (2) 1uf not (4) .1uf correct? Does it work better than the stock LarMar PPIMV with just (2) .1uf mustards?

xenrelic · Post by **xenrelic** » Fri Feb 01, 2013 9:11 am

Yeah, I notice a little extra gain with this version but not necessarily good sounding. I much prefer the larmar PPIMV over this version.

TJB · Post by **TJB** » Fri Feb 01, 2013 9:38 am

Thanks, I'm just about to order the LarMar as we speek. Marks clips always sounded good to me so I will give it a try.
Bray must really like those green mylar caps for some reason. I may try the .33uf/820R but not sure if I shuold go with nos mustards or electrolytic or some other kind.

I think his mods sound good but I also think maybe too much low end signal for the lower filtering 32uf x32uf on screens, pre amp and PI

xenrelic · Post by **xenrelic** » Fri Feb 01, 2013 10:24 am

Try out the Sprague PS caps available over at Antique Electronic Supply: http://www.tubesandmore.com/products/C-S-600

Those sound just as good as mustard caps, if not better in some designs. I think they sound better in higher gain circuits IMHO.

I've been using those exclusively since SoZo has been hit and miss with shipping, plus I just can't justify spending that much on a capacitor anymore when these PS caps sound just as good.

It looks like Bray was using those green dipped Mylar caps because they actually sound a bit better than the stock metalized polyester caps. The 6PS polyester film and foil orange drops are far better tone-wise than the green dipped caps and metalized poly caps.

I really dig the CDE DMT series polyester film and foil caps as well. Those sound amazing in newer Marshall amps like the DSL, TSL and JVM type circuits. Plus they are very high quality with thick leads. If you're in need of a radial style cap that doesn't take up too much space, I would definitely consider the DMT caps.

It's kind of funny that the color of the DMT capacitor is the same as wet Mimosa Hostilis inner root bark powder, which contains a high amount of a psycho-active compound known as D.M.T. that is also found naturally in the human brain and is believed to be responsible for inducing the dream state we experience during sleep. It's primarily used by South American Shamans for healing wounds and treating skin problems, but is also used for spiritual visions in their "Ayahuasca" brew when mixed with a natural MAOI like Banisteriopsis Caapi vine or Peganum Harmala ("Syrian Rue seed"). I wonder if that had anything to do with why CDE named that capacitor series "DMT". *giggles*

TJB · Post by **TJB** » Fri Feb 01, 2013 10:55 am

Thanks for the info!
Yeah, I do have some Sprague 225P .68uf orange drop and some vintage CDE WMF 1P68 .68uf that seem to be working ok in a couple circuits. Not paying those insane prices for the nos mustards anymore. I will check out those DMT caps. Thanks!

Metropoulos Forum

David Bray, Metro amp mod sound clip

hmm

Re: hmm

Re: David Bray, Metro amp mod sound clip

Re: David Bray, Metro amp mod sound clip

Re: David Bray, Metro amp mod sound clip

Re: David Bray, Metro amp mod sound clip

Re: David Bray, Metro amp mod sound clip

Re: David Bray, Metro amp mod sound clip