Hello: I am new to this group (first post here) and am also owner of a fairly beat-up Randall RG-80 (circa 1983). I have been working on it (which I detailed on another amp forum so I won't go into it here), but this being a forum dedicated to Solid state I am wondering if there are any fans of the RG 80 here? By fans I mean that you use one and like it. I really dig it (despite the hum problem I am working on), the "red" channel is really fun when cranked, it is quite loud for what it is.
I'm a fan. I bought two, new, when they first came out. Actually drove down to the factory to pick them up and to spend a couple of hours with designer Gary Sunda who explained the whole genesis of this amp. Many years later I sold one, the other was stolen. After a few years I missed it and bought one used. Then another. Then a wrecked chassis. Now I have 4 in various states of repair. It's a very good design, sounds good, nearly bulletproof and sounds better the more you turn it up. I got interesting results by using a 16 ohm Celestion instead of the stock 8 ohm unit. It dropped the power output somewhat. Since the amp sounds better the more you turn it up, I'm able to turn it up more often.
An interesting side note is that a lot of the weight of these amps is in the MDF cabinet. If you put the chassis in a pine or plywood cabinet, it's amazing how nice and light they really are.
Great amps.
Really groundbreaking.
Simple, yet they sound better than many who came later, and can hold their own on stage even today, maybe with some nice pedal driving them for the heaviest stuff.
Not that they are shy in that aspect !!
I've never heard on in person, but I like what I hear on youtube.
Quote from: J M Fahey on February 02, 2011, 03:22:51 PM
...Really groundbreaking....
J.M.: What part of the design do you consider the ground-breaking part? Or do you mean the sound is groundbreaking? I know that I like it but I don't have enough knowledge to know what makes it great.
QuoteJ.M.: What part of the design do you consider the ground-breaking part? Or do you mean the sound is groundbreaking? I know that I like it but I don't have enough knowledge to know what makes it great.
Both.
1) They used FETs the *right* way, nothing mysterious there, they designed gain stages around them, fed them the proper voltage, *biased* them, what every designer does.
They used the values that came out from calculation.
2) Most SS amps in that era were basically Hi Fi designs (including Baxandall tone controls) , shoehorned into guitar amps (see Peavey, Crate , Kustom, etc. from that era); Randalls were designed from the first second as Guitar amps.
They are still usable today ...and they come from the 70's !!!!!
I have one that I got used for $40.00. Ha! the Celestion is worth moe than that! I think it sounds pretty good. I don't like both channels at the same time though. If I were going to use it as my main amp, I think I would find a way to disable that feature.
You just need the footswitch.
Also, even with the switch, I turn down the gain and volume on the channel you're not using. If you are on green, the red channel can still assert itself.
I have the footswitch. It has two buttons. If you push one, it switches between channels. If you push the other, it turns on both channels, then if you push the wrong button to turn off the other channel it turns off the light on the other channel, but leaves some sound coming through it. Then you have to hit the buttons in the right order to turn it off. Like I said before, if I was going to use it regularly I would probably disable that second button. I don't like the sound of both channels together anyway.
Well, it *is* an old amplifier after all.
Switching is somewhat primitive, although not worse than what was used on, say, a Twin Reverb.
Both channels are *always* "on", the pedal just grounds the output of either of them, so the other one can sometimes be faintly heard in the background. Oh well.
The second "both on" switch only lifts the ground connexion at the footswitch pedal itself, so by definition non can be grounded (so both sound at the same time).
A useless setting in my opinion.
Anyway, the sound is killer and that's what matters.
Yeah, You're right. Did I mention I only paid $40.00 for it? ;D
Post a couple pictures :)
Guts and speaker would be interesting, besides a couple external ones. ;)
Here are some shots. As you can see it's pretty beat. I had to re-tension the footswitch jack and clean the pots. One of the pots is still a little funky, but good enough for home use. It sounds great. I had it about a year before I found out about the pull knob for more distortion. The wah on the floor is a Clide McCoy that I got on a local on-line (oxymoron?) police auction for $11.00
http://i858.photobucket.com/albums/ab141/dmartn149/th_DSC00080.jpg?t=1299114419
http://i858.photobucket.com/albums/ab141/dmartn149/th_DSC00082.jpg?t=1299114419
http://i858.photobucket.com/albums/ab141/dmartn149/th_DSC00081.jpg?t=1299114419
Looks familiar.
Do you have any issues with hum, by the way? I have low hum that I can't figure out yet and hiss in the reverb circuit. I dig the reverb (even with the hiss) on this.
A mighty old warrior.
And the Celestion speaker is the cherry on the cake.
You posted the thumbnails.
The full size pictures are:
(http://i858.photobucket.com/albums/ab141/dmartn149/DSC00080.jpg?t=1299114419)
(http://i858.photobucket.com/albums/ab141/dmartn149/DSC00082.jpg?t=1299114419)
(http://i858.photobucket.com/albums/ab141/dmartn149/DSC00081.jpg?t=1299114419)
Amp pictures are best taken outside, in a hazy dat or when the Sun is covered by a cloud, for strong yet relatively shadow free light.
If no other way, try to shed some light on the front and support your forearms with a chair or some books as to avoid vibration.
Also push the button smoothly, avoiding jerk.
Anyway, thanks for the pictures, and someday if you open it for something else, post some gut (boards) pictures too.
Thanks again.
I just ran up stairs and snaped those. When i take ebay shots I use a tripod, lots of lights, and the timer.
I'd love to play one of these someday. What's with the On-Off-On power switch?
QuoteWhen i take ebay shots I use a tripod, lots of lights, and the timer.
So, *we* are some kind of second-rate humans??
:'( :'( :'( :'( :'( :'(
Wait until I tell my Mom !!! :trouble
Hi joecool: the power switch is inverting, as to invert the "grounding cap" position; he may leave the switch as-is but should pull the capacitor and install a proper 3 pin grounded power cable.
It looks better in full size.
I think these do have a three-prong plug, but still with line-cap-to-chassis.
The plug is a three prong.
I just got this big bro. on craigslist for $20.!!!!! The young lady was moving and wanted it out ASAP. Her uncle had given it to her years ago when she thought she wanted to play guitar. She said it has been in storage for at least ten years. It is pretty good cosmeticaly, sounds great except for the hum. Turn on the reverb and tremolo and it makes a perfect "surf" guitar sound.
http://i858.photobucket.com/albums/ab141/dmartn149/randall120002.jpg?t=1301448019
Quote from: dmartn149 on March 29, 2011, 09:31:59 PM
I just got this big bro. on craigslist for $20.!!!!! The young lady was moving and wanted it out ASAP. Her uncle had given it to her years ago when she thought she wanted to play guitar. She said it has been in storage for at least ten years. It is pretty good cosmeticaly, sounds great except for the hum. Turn on the reverb and tremolo and it makes a perfect "surf" guitar sound.
http://i858.photobucket.com/albums/ab141/dmartn149/randall120002.jpg?t=1301448019
Now THAT'S a deal!
Bravo! Craigslist is a good source. People just want it out of their garage or closet and if they don't play it doesn't mean a thing to them. Tell us how you progress with fixing the hum.
I will. Actually, I'll probably be asking for help. I haven't had time to even pull the chassis yet, but when I do I'll give it a good cleaning and see if that helps. There are a couple of big caps sticking down from the chassis. Can those cause hum on a SS amp like they can on a tube amp?
The date codes on the speakers show they were made in 76. Now I'm really impressed with the condition.
Quote from: dmartn149 on March 30, 2011, 08:54:49 PM
I will. Actually, I'll probably be asking for help. I haven't had time to even pull the chassis yet, but when I do I'll give it a good cleaning and see if that helps. There are a couple of big caps sticking down from the chassis. Can those cause hum on a SS amp like they can on a tube amp?
The date codes on the speakers show they were made in 76. Now I'm really impressed with the condition.
Sure can. Electrolytic caps "wear out" with age (I won't bore you with the details unless you are curious). Basically they will cause voltage problems and frequently lots of hum when they crap out. Some are good for only 10 years, others 30 or 40. This amp has caps that are 35 years old, I'd say time to replace!