Want Pre500 tone? Here's how to get it!

[R_ADKINS80]

So after much experimentation, bugging some of you with pm's (sorry guys), and awesome conversations with both Mike B and George M this week, I figured out why my recto was just shy of the tone I was chasing:
I soldered the LDR's I hastily removed back in (LDR 3 and LDR 10, they have to be there, they run in parallel with the jumpers I installed), I noticed the difference immediately, I got the drive and bite that I was missing.

Now after jumping the gun in the past, now I can say I'm happily getting pre 500 tone :twisted:

I have electronics background and I don't see putting those back in making any difference what so ever. Any thing in parallel with a jumper is going to get bypassed completely as the current will take the path of least resistance. Since a jumper is a short circuit, it should make no difference if an ldr is in parallel with it or not. Weird.

 

[JCDenton6]

It is weird... but it works :?

 

[R_ADKINS80]

Now if only I could figure out how to get my ch 2&3 to sound boosted without having to use a tube screamer that way i can switch to clean without tap dancing I would be set.

 

[JCDenton6]

Is your amp still wired stock with switches?

 

[R_ADKINS80]

No I took the cathode resistors back out and also the cap off of v2. The switching didn't work.

 

[Third Age Amps]

R_ADKINS80, Do you have 1M gain pots or are they 250K? If they are the 250K, you can install a 500k or 1M pot and it will give you the gain boost you're looking for.

 

[R_ADKINS80]

they are 1 meg, but I am still using the tube screamer as a clean boost. The one meg pots didn't really help in that aspect. They did clean up the sound a little but it's still not a sub for an OD pedal.

 

[JCDenton6]

Hmm... have you tried removing the 2m/20pf circuit and leaving the 680k/.002uf circuit intact?
That should tighten things up a little bit, you can even swap the 680k for a 470k and drop the cathode caps like Third Age Amps suggested in the Henric modded triple thread.

 

[R_ADKINS80]

Guess i know what I'm doing this weekend lol.

 

[Third Age Amps]

I prefer .47uf on the first two stage's bypass caps, but .68 will work just as well. I just wanted a bit more mid/high-mid bite.

 

[R_ADKINS80]

Hmm... have you tried removing the 2m/20pf circuit and leaving the 680k/.002uf circuit intact?
That should tighten things up a little bit, you can even swap the 680k for a 470k and drop the cathode caps like Third Age Amps suggested in the Henric modded triple thread.

Just removed that circuit.....WOW! That was a pretty awesome improvement in tone, and tightness. This thing is turning into my own Recto-Beast. Need to hit the surplus store tomorrow and grab some caps and resistors to play with.

 

[R_ADKINS80]

Removing those two components did, however, make the presence control on ch2 a "do nothing" control. tt has no change on the tone what so ever now lol.

 

[JCDenton6]

^ That happened to me when I clone orange to modern on my 2 ch Triple, the knob has no effect until I get past 12:00.
I like that though, livened up that channel a bit.

 

[R_ADKINS80]

I was looking over the schematic last night, i know where the cathode caps are, but I don't see the "coupling" caps that were mentioned by third age....where are they?

 

[Third Age Amps]

Coupling caps are any capacitors that are coupling one stage to another. C21, C9, C10, etc ...

 

[fretout]

Like a few of the other forumites, I've owned quite a few Rectos through the years, and I've settled into my two Blackfaces...one is a Pre-500 (with 1M pots), and one Rev.G. I like both versions for separate reasons...the Pre-500 has the best hi-gain tones, and the Rev.G has the most best mix of great hi-gain and decent cleans.

I think any and all myths that can be revealed about these amps is definitely a great thing! Since I picked up my Rectos, I've discovered that the Mark series amps are "my sound". I wonder about how close these mods get to the actual Pre-500 tone. Just like the Mark IIIs can be scoped identical to the Mark IIC+, but, one thing the transformers do is affect the overall "feel" of the amp. My pre-500 has the Mark III transformers. I wonder if even tonally the other revisions can be brought "down to spec" to the earlier revisions, I wonder if there is anything lacking...

 

[screamingdaisy]

The Mark III tranny was used up to somewhere around serial number 2200, so Rev C, D, E and F.

 

[YellowJacket]

The Mark III tranny was used up to somewhere around serial number 2200, so Rev C, D, E and F.

Well, SOME Rev F Rectos have the Mark III tranny -most probably do- but mine does not. Mine sits about 26XX and it has the same Tranny as the REV Gs but the The Diode Rectifier and the Choke are the 'early dual' parts. It sounds like a Rev F early dual, it's brighter and tighter than the Rev Gs. I think the real components producing the tone are the resistors that have been discussed in this thread. I suspect the trannies do a lot less to colour tone.

 

[JCDenton6]

Here is a little clip I recorded with my turtle beach gaming headset (WHAT?!?) at mousefart volumes :lol:
I won't have my shure SM57 back for a while.

http://dl.dropbox.com/u/47381724/Screwing%20Around.mp3

Tone controls at 12:00 with gain at 9:00, unboosted.
What do you guys think, proper pre 500 tone?

 

[TheMadMacBook]

So I realise that this thread has evolved a lot from when it started, and after reading the whole thread multiple times, and I've come to the conclusion, that I'm pretty lost in what the answer to a nicely modded 2ch rectifier without rewiring any gain stages or anything too complicated is.

I think it could be nice, if you guys could do a little step on step like the first post, and help out someone like me, without the extreme knowledge about engineering, and what stuff like 2m/680k circuit actually means..

Would really appreciate it!