ampeg gs-12r reverberocket ???

[Galapogos17]

I just purchased a used '65 Ampeg GS-12R Reverberocket and I am trying to get it up an running. I had all the general maintenance done, changed filter caps, checked tubes and replaced reverb tank. The only things left are the speaker and transformers. Here are my problems...

1. How loud should this amp be? I have a 5watt silvertone combo that's louder.
2. How much clean head room should this amp have? It starts to distort when the volume is around 9-10 o'clock. At that point it doesn't get louder, just more distorted I hooked it up to another speaker cab and that helped a bit, but still very quite and distorted too soon.
3. It is a very muddy distortion. Chords sound terrible. Clean tone is muddy as well.
4. Thinking of Eminence Canis Major as a replacement speaker. Any other recommendations?

I got the amp for $270 and have about $260 in it. Does this amp have some potential in it? The trem and reverb sound great. I feel like the next step would be to replace the speaker and upgrade to mercury transformers. I was looking for a fender princeton reverb and wonder if I should just cut my losses and put funds towards that purchase or can this amp get me in the ballpark of a princeton or deluxe reverb?

thanks!

[ozspawn]

Does it have the wimpy CTS speaker in it?

If so, that's your problem.

I have a '66 RR II, but it's been slightly modified.
I have Philips 6L6's in it (the circuitry was slightly
modified for this) and a reconed Magnasonic speaker.

This thing sounds awesome. I'd put it against
any of my other amps, including my '66 Deluxe Reverb
(with Telefunkens and Brimars) or my '69
Princeton Reverb (with Telefunkens and RCA 6V6 GTA's).

The RR II has an Amperex in V1 and sounds
airy, spongy, and warm with a creamy overdrive.
The reverb is kind of spacey (which I like) and the
Trem is the best I've heard. It has almost as much
headroom as my DR.

My advice: do not give up on this amp.

[Galapogos17]

Thanks for the input ozspawn. The original speaker is some no name speaker. It doesn't look like the original Jensen. It sounds like mine is putting out some weak power, which leads me to believe it's the transformer.

[slider313]

Was the FP twist-lock cap changed? I've seen more than a few Ampegs the had supposed cap jobs with the original can. It should be either a 70/40/40/20@450v or a 70/40/30/20@450v. The amp should be clean and a bit thin until you hit 6-7 on the volume then it should thicken up a bit and stay clean until 9-10 on the volume where it gives it up.

[bunuel]

1. How loud should this amp be? I have a 5watt silvertone combo that's louder.

Something's definitely still off--the GS12R should be pretty durn loud for their wattage, way louder than an 5 W S-tone. Even with a very inefficient spkr.

They are well worth bringing back. Fantastic amps that are every bit as good as a DR.

[Galapogos17]

My tech left the original can in disconnected and added four new individual caps. I am not sure what the values are. I can ask him tomorrow.

[Galapogos17]

Thanks for all the input thus far

[erksin]

It should be around 18 watts and have a lot of clean headroom before breaking up into a pretty tight crunchy breakup. Sounds like more than just a speaker issue to me.

[Galapogos17]

thanks erksin, any other things I should check out?

[Galapogos17]

Anyone else?

[slider313]

I agree with erksin. If it was recently worked on, I would go back to the tech and ask him to go back over the amp.

[Galapogos17]

It's still with the tech. He is off today, so I will be meeting with him tomorrow.

[FFTT]

Yeah that amp should sound huge.

My '64 R12R ships tomorrow! Can't wait!

[Galapogos17]

Hey fftt, thanks for the words on encouragement!

[Galapogos17]

Was the FP twist-lock cap changed? I've seen more than a few Ampegs the had supposed cap jobs with the original can. It should be either a 70/40/40/20@450v or a 70/40/30/20@450v. The amp should be clean and a bit thin until you hit 6-7 on the volume then it should thicken up a bit and stay clean until 9-10 on the volume where it gives it up.

Yep those caps were replaced and at the proper voltage. I ordered a new speaker and output transformer. I hope the output transformer fixes the issue. I should know by this time next week.

[Galapogos17]

What is the difference, in terms of it effecting the sound, between using the can cap or using four seperate values listed in within the can?

[slider313]

There's no difference in sound. The cap can was used for reasons of limited space. Today's electrolytics are quite small compared to the mid 60's Mallorys or Astrons.

[FFTT]

The efficiency of the driver makes a HUGE difference with these amps.

The original CTS 15 watt AlNiCo's and ceramics were not very efficient, maybe
around SPL of 97, where most of the modern speakers are rated SPL 100-102.

If you followed my R12R clip thread, I just blew the original driver in a blaze
of glory.

We installed an Emi C-Rex and now the amp is easily twice as loud.
Unfortunately, now the amp has too much bass response with that driver.

I really prefer the tone and the recording volume of the original CTS AlNiCo driver, but
it simply was not intended to handle power chords with the amp wide open.

Eric tested the the R12R's output and it was putting out 21 watts clean RMS with
a peak of 28 watts wide open.

With an efficient driver the amp sounds more like 40 watts or higher.

[Galapogos17]

Thanks for all the input! I put a Canis Major in the amp. I should get it back in the next few days. I will let you know how it sounds.

[bunuel]

The original CTS 15 watt AlNiCo's and ceramics were not very efficient, maybe
around SPL of 97, where most of the modern speakers are rated SPL 100-102.

If you followed my R12R clip thread, I just blew the original driver in a blaze
of glory.

I really prefer the tone and the recording volume of the original CTS AlNiCo driver, but
it simply was not intended to handle power chords with the amp wide open.

Eric tested the the R12R's output and it was putting out 21 watts clean RMS with
a peak of 28 watts wide open.

With an efficient driver the amp sounds more like 40 watts or higher.

I've posted this elsewhere, but to repeat: I'm lucky enough to have bought a coupla vintage ampegs yrs ago directly from great Jess Oliver, the designer of most of the early great ampegs (& still doing amp tune-up & repair in NY, last I heard). He was emphatic that no one should play the early ampegs full out for long periods of time w/ the oem spkrs, unless they wanted to blow 'em. The early amps all have spkrs that are easily blown for 3 reasons: 1) at the time no one expected folks to be playin 'em dimed for extended periods; 2) the output ratings were overly conservative; 3) the "bean-counters" (his term) at ampeg were trying to cut costs by putting in the lowest powered spkrs possible.

He recommended going with a speaker rated for at least 12-20 watts more than what the amps were rated at output-wise. He'd put in vintage Jensen c12n in both reverberockets I picked up from him to replace the Jensen c12rs that were oem.

[FFTT]

The low output of the amp was quite misleading, sounding more like a 10 watt amp due to the speaker's low efficiency.

It makes perfect sense that back in '64 these amps were designed for
beautiful low volume cleans with Reverb and Tremelo.

The amp stayed clean up to just under 1/2 volume at about 11:00

When the speaker failed, I was barely strumming at 1/2 volume while messing with the Tremelo controls trying to get the speed right.

I agree that this amp deserves a much better quality driver, rated
30-50 watts RMS, but I prefer AlNiCo's for their smoothness and
shimmering details.

The amp can be very dark with the wrong driver.

I've posted this elsewhere, but to repeat: I'm lucky enough to have bought a coupla vintage ampegs yrs ago directly from great Jess Oliver, the designer of most of the early great ampegs (& still doing amp tune-up & repair in NY, last I heard). He was emphatic that no one should play the early ampegs full out for long periods of time w/ the oem spkrs, unless they wanted to blow 'em. The early amps all have spkrs that are easily blown for 3 reasons: 1) at the time no one expected folks to be playin 'em dimed for extended periods; 2) the output ratings were overly conservative; 3) the "bean-counters" (his term) at ampeg were trying to cut costs by putting in the lowest powered spkrs possible.

He recommended going with a speaker rated for at least 12-20 watts more than what the amps were rated at output-wise. He'd put in vintage Jensen c12n in both reverberockets I picked up from him to replace the Jensen c12rs that were oem.

[Galapogos17]

I got the amp back today! The new mercury output transformer really brought the amp back to life. The volume is much greater and the terrible distortion sound is gone. Now when the amp breaks up it's a nice overdriven sound. I would say you guys were right on the money about it being as loud as a deluxe reverb.

The speaker was a good choice too. I can't wait until it breaks in. I wouldn't call this amp dark by any means, it's just not as in your face as say a fender.

Overall really glad I put some money into this thing to getting running again. The repeat percussion trem sound is just amazing!! I also really enjoy the reverb on this amp.

Thanks again to everyone for their input.