matamp/orange PA conversion

For those building and repairing amps on their own. Learna and share ideas.

matamp/orange PA conversion

Postby ThisLifeILead on Tue Jan 29, 2013 1:59 pm

viewtopic.php?f=4&t=101914
Here is the start of the process. Basically a huge tube PA that im converting to a matamp/orange style amp. I am just organizing my mouser order for the required parts. Pics of thr chassis are posted in link. Figured this is a better place for it.

Mouser order done, now i wait....*rubs hands together* muahahahahahahaha
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Thu Feb 07, 2013 6:12 pm

Ha nobody interested in this conversion? Well the parts arrived, goona start the hacking and will post my progress with pics as she goes.
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby 57lpjr on Thu Feb 07, 2013 6:39 pm

Please do post pics of the build!!!
I have more gear than I need...but not as much gear as I want...

"Roll over Woodstock - we won!" & "Music is life, and life is not a business." (Iggy Pop 3/15/10)

"but lately one or two has fully paid their due for working for the clampdown...HAH, Gitalong, Gitalong"

"I believe, believe, believe, that there's better days ahead. I believe, believe, believe, that there's a heaven before I'm dead."

"I'll play for free but I gotta get paid for breaking my s**t down at the end of the night"
57lpjr
Ampmeister
 
Posts: 4596
Joined: Mon Jul 19, 2004 7:01 am
Location: Fortress of Amplitude, Syracuse, NY

Re: matamp/orange PA conversion

Postby ThisLifeILead on Wed Feb 13, 2013 3:58 am

Got the input and FAC wired up. Used values 0.047uf, 0.022uf, 0.01uf, 4700pf, 2200pf, 1000pf.
sorry pic kinda sux
Image

Uploaded with ImageShack.us
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Wed Feb 13, 2013 3:16 pm

here is the schematic im working from again. I am omitting the Drive control. My question is, is if were to be keeping the reverb where would i tap off from to feed the reverb circuit. the reverb has 3 stages of gain. 1 on the input and 2 on the recover. I was thinking of taking the signal right after the first gain stage between the 47n cap and the FAC (bass boost) control and then feeding it back at the master volume. any thoughts?

I prob should have done the power supply first but i wanted to get the preamp in so i can fire it up, take voltage readings and then go back to the power supply and tailor it to the voltages i need. :jam:

I got so much room in there i am going to use two sockets for the first two stages so everything wont be so tightly packed on just one.

http://img585.imageshack.us/img585/9639/gt100.gif
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Mon Feb 18, 2013 5:40 pm

Got the Boost circuit in,NFB, effects loop all wired up (right side) All that is left to wire is the Reverb control, reverb footswitch and PPIMV.

My issue is the neon lamp right in the middle. The lamp itself is coming out of the housing so I was thinking of just removing it, putting my reverb control there with the footswitch and get some small LEDS to fit on the right side. I always loved my Traynor YSR-1 how it had a green lamp and a red lamp for in standby and go time.once i have the amp tweaked and going ill look further into getting an indicator lamp wired up in the same fashion.

Im not fully convinced with that shielded wire from the effects to the P.I. I have a feeling i am going to be tweaking that.

Image

Uploaded with ImageShack.us
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Wed Feb 27, 2013 2:10 am

Well i finished the PPIMV, EL34 grid stoppers and bias blend resistors. Verified all my wiring and fired her up.....found some voltages off. Rocking a healthy 526vdc on the plates :shhh:

Found my first 2 gain stage voltages too low. Raised the plate resistors from 220K to 100K. Voltages are bang on now. for the P.I plate resistors i had to increase the plate resistor on the cathode follower from 100K to 150K and reduced the 3rd gain stage from 390K to 360K. voltages are close but not quite bang on. gotta do the math for tolerances before i start doing more swapping.

With no shielded wire on the MV, just twisted wire, its actually suprisingly quiet. got alitle hum with the master dimed but its not that noticeable with how loud the friggin thing is.
SOUND NOTES: Ok this thing sounds like a dream. I play in a few different tunings but mostly Drop C, C standard. I only tested it with Drop C and let me tell you!!.
This is a slugde metal monster!!! it has such clarity even tho it is distorted. Sustain!! Sustain Sustain!!! With just a tiny roll off the volume knob it cleans up really well. I never tried the effects loop yet. The inductor boost is pretty friggin cool! i find it adds sparkle and helps with note articulation. Wayyyy better then ANY presence control ive tried.
When i have the Master dimed or near dimed it sounds like my speakers are torn. really nasty. I have to scope the signal to see whats goin on in there but its almost complete (reverb is goona wait until i have the amp tweaked). I think i found my new giggin amp. Hopefully the effects loop works good, Will post finished pics and Some recordings shortly. I got a set of recording mics to test out :p :cheers:
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Wed Feb 27, 2013 5:40 pm

Preamp voltages are within 10%.im happy with that
. Going to scope signal and get the reverb hooked back up....pics tonight.
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Tue Mar 05, 2013 3:50 am

Forgot 680pf cap across 3rd gain stage plate resistor. weird noise gone. Put a bright bypass cap on gain pot. Amp is quiet and has an amazing rock tone in standard E tuning, Dropped ...sounds super thick and in your face. I left the neon lamp in and it looks like its not causing any extra noise.
Will get some recordings done here this week :-)

This amp goes against everything ive heard about ORMATS and headroom. This amp has zero headroom. With the Master dimed and the gain on 1 i still get breakup. Not that its a bad thing. I roll the volume down on my guitar and she cleans up beautifully.. is this normal or am i getting too much drive in the preamp? Using a scope i can see the wave square off pretty early tweaking the gain pot..

i think im talking to meeself :shhh:
Last edited by ThisLifeILead on Wed Mar 06, 2013 2:43 pm, edited 1 time in total.
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

ECHO LOOP MODS>?

Postby ThisLifeILead on Wed Mar 06, 2013 2:41 pm

I want to use the echo loop or modify it so i dont have my time based effects upfront in the amp. I cant seem to find any documentation about modding the echo loop. Because its a clone im not worried about making holes in the chassis or devaluing anything. Can i just replace the 100K bleed resistor in the echo loop with a 100K pot to blend dry and wet signals? anybody have any experience with this?
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Fri Mar 08, 2013 4:33 am

Never mind that wont work lol. I hooked the reverb up but its not working properly i am going to have to do some tinkering and scope it out. i think im getting some bleeding from the reverb circuit.I decided i am going to put the cathode bypass caps on the first two gain stages on a switch on the front panel. I got the realestate might aswell use it...pics and clips soon :)
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Mon Mar 11, 2013 3:23 pm

Screw the verb, screw the echo loop :twisted: . I tinkered with it all weekend and im not happy with it.
Pulling it all out. and goona use the verb parts on another amp build. Reverb trans and pan.
"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies

Re: matamp/orange PA conversion

Postby ThisLifeILead on Wed Mar 13, 2013 3:19 am

"Great spirits often encounter violent opposition from mediocre minds" - A.Einstein
ThisLifeILead
Squire
 
Posts: 582
Joined: Fri Feb 12, 2010 6:15 pm
Location: frozen prairies


Return to Do It Yourself Amp Builders

Who is online

Users browsing this forum: Bing [Bot] and 1 guest