Identify this Recitifer Revision: F or G?

[Bad.Seed]

Trying to identify this Rectifier that I'm looking to buy. It's a small logo, but the serial number leads me to believe that it's an early Rev G, the Parallel effects loop also brings me to this thought.

I'm not super knowledgeable on the subject, but the forum threads I've looked up don't really seem to be decisive either, so I figured I'd see if anyone here can help

Here are some pictures:

 

[Wizard of Ozz]

Revision G

The change from F to G was somewhere in the mid-late 3500-3800 serial numbers. If you open it up you'll see the Rev G label near the edge of the main pcb beside the 4 30uf 500V filter caps.

 

[Snave]

Above is true. No need to open it up though. No Rev Fs came with parallel loops. Many early Rev Gs still had serial loops, small logos and attached power cords.

 

[maddnotez]

What are the differences (besides that loop)? I know nothing about these amps but just checked out 1 comparison on youtube and they sound identical.

 

[Snave]

What are the differences (besides that loop)? I know nothing about these amps but just checked out 1 comparison on youtube and they sound identical.

I've owned a lot of Rectos (F, G, 3 channel) and kept a 1993 Rev F for 9 years. The reality is the loop is the biggest difference and tonal changes beyond Rev C-E are overblown. F is supposedly tighter than G, and while there are circuit differences I think a big part of this is placebo and 9/10 guys are boosting their Rectos, so what difference does it make?

Like other "older is better" amp models, a lot of supposed tonal differences are fairy dust blown by sellers. Same as the "rackmount Rectos sound better" and "block letter 5150s are best" myths. Different transformers were used until sometime 1993, but whether these are better is debatable. They weren't magic--they were just what was already used in Mark III and IVA amps. The transformers that replaced them until recently were the same as Mark IVB amps. Mesa Boogie is pretty utilitarian as far as "boutique" amp makers go.

For what it's worth, Silverwulf/NewWorldMan has owned more Rectifiers than probably anybody on the planet and his favorite is the Rev G.

There's a bigger difference between any 2 channel Recto, the 3 channel Solo Heads, and the newer Multiwatt models than between Rev F and Rev G. Can anyone tell them apart in this video though?

 

[maddnotez]

What are the differences (besides that loop)? I know nothing about these amps but just checked out 1 comparison on youtube and they sound identical.

I've owned a lot of Rectos (F, G, 3 channel) and kept a 1993 Rev F for 9 years. The reality is the loop is the biggest difference and tonal changes beyond Rev C-E are overblown. F is supposedly tighter than G, and while there are circuit differences I think a big part of this is placebo and 9/10 guys are boosting their Rectos, so what difference does it make?

Like other "older is better" amp models, a lot of supposed tonal differences are fairy dust blown by sellers. Same as the "rackmount Rectos sound better" and "block letter 5150s are best" myths. Different transformers were used until sometime 1993, but whether these are better is debatable. They weren't magic--they were just what was already used in Mark III and IVA amps. The transformers that replaced them until recently were the same as Mark IVB amps. Mesa Boogie is pretty utilitarian as far as "boutique" amp makers go.

For what it's worth, Silverwulf/NewWorldMan has owned more Rectifiers than probably anybody on the planet and his favorite is the Rev G.

There's a bigger difference between any 2 channel Recto, the 3 channel Solo Heads, and the newer Multiwatt models than between Rev F and Rev G. Can anyone tell them apart in this video though?

I can definitely notice the difference here.

But the video I watched was a Rackmount G ( I think ) vs an F.

Identical. Could have been some trickery, who knows.

 

[psychodave]

What are the differences (besides that loop)? I know nothing about these amps but just checked out 1 comparison on youtube and they sound identical.

I've owned a lot of Rectos (F, G, 3 channel) and kept a 1993 Rev F for 9 years. The reality is the loop is the biggest difference and tonal changes beyond Rev C-E are overblown. F is supposedly tighter than G, and while there are circuit differences I think a big part of this is placebo and 9/10 guys are boosting their Rectos, so what difference does it make?

Like other "older is better" amp models, a lot of supposed tonal differences are fairy dust blown by sellers. Same as the "rackmount Rectos sound better" and "block letter 5150s are best" myths. Different transformers were used until sometime 1993, but whether these are better is debatable. They weren't magic--they were just what was already used in Mark III and IVA amps. The transformers that replaced them until recently were the same as Mark IVB amps. Mesa Boogie is pretty utilitarian as far as "boutique" amp makers go.

For what it's worth, Silverwulf/NewWorldMan has owned more Rectifiers than probably anybody on the planet and his favorite is the Rev G.

There's a bigger difference between any 2 channel Recto, the 3 channel Solo Heads, and the newer Multiwatt models than between Rev F and Rev G. Can anyone tell them apart in this video though?

I’ve been in a music room with Revisions C E F and G and I could easily hear tonal differences along with feel. The C was pretty bright sounding and my least favorite. The G was the darkest sounding. I preferred the F the most. Keep in mind they are all still rectos and share a similar base sound. Also, some people don’t have the same discerning ears as others. YMMV.

Personally I think the effects loops on rectos suck tone, but are necessary if you want to get the rectos to sound good at home levels.

I’ve owned dual and triple revision F amps and they are not all created equal. I had a dual recto that crushed. The new owner swears it’s the best Rev F he’s heard and as I understand it, he’s owned a lot. He also lives near boogie and has had lots of custom stuff made as well. I was glad to get rid of it. lol

All said and done, rectos sound best turned up loud to where the power tubes start to compress, but not too loud where they over compress and kill the amps feel. Just my .02.

 

[Snave]

The difference in the video I linked may be noticeable, but in a blind test I doubt a significant percentage could tell which is the "inferior" 3 channel amp. I can definitely hear the difference between Lasse's Rev F head and Rev G rack head, but the rackmount one has a replaced Mercury Magnetics OT.

To Dave: I noted in my second post that tones differences beyond Rev C-E are exaggerated. The tone of those initial revisions is noticeably different from any later ones. I agree the effects loop sucks tone (especially low end, some highs too). This is because of a poorly chosen cap value in the stock loop design. I called Mesa about fixing this and Mike B. confirmed there is a loop tone suck mod. I got it done when I had my Rev F recapped last year.

"There is a 2.2uf capacitor connected to pin 3 of tube V4a (which is the effects loop recovery stage). Changing this to a 10uf tantalum capacitor should eliminate the tone suck or at least reduce it substantially. Just be sure to install it in the right direction with the "+" end connected to pin 3. This worked great for me."

I can't guarantee the above replacement value is the same that Mesa used, but that is the cap that they replaced and it makes sense that a higher value would neuter less signal. This mod is more important than transformers or special tubes if anyone here has a serial loop they leave on all the time. Nobody talks about this mod for some reason and just dismiss the loop as being bad.

 

[psychodave]

The difference in the video I linked may be noticeable, but in a blind test I doubt a significant percentage could tell which is the "inferior" 3 channel amp. I can definitely hear the difference between Lasse's Rev F head and Rev G rack head, but the rackmount one has a replaced Mercury Magnetics OT.

To Dave: I noted in my second post that tones differences beyond Rev C-E are exaggerated. The tone of those initial revisions is noticeably different from any later ones. I agree the effects loop sucks tone (especially low end, some highs too). This is because of a poorly chosen cap value in the stock loop design. I called Mesa about fixing this and Mike B. confirmed there is a loop tone suck mod. I got it done when I had my Rev F recapped last year.

"There is a 2.2uf capacitor connected to pin 3 of tube V4a (which is the effects loop recovery stage). Changing this to a 10uf tantalum capacitor should eliminate the tone suck or at least reduce it substantially. Just be sure to install it in the right direction with the "+" end connected to pin 3. This worked great for me."

I can't guarantee the above replacement value is the same that Mesa used, but that is the cap that they replaced and it makes sense that a higher value would neuter less signal. This mod is more important than transformers or special tubes if anyone here has a serial loop they leave on all the time. Nobody talks about this mod for some reason and just dismiss the loop as being bad.

Wish I had know about the loop mod/fix. I probably would have kept a Rev F. Thanks for the post.

 

[Shask]

Personally I think the effects loops on rectos suck tone, but are necessary if you want to get the rectos to sound good at home levels.

I am curious how you use the effects loop to improve the low volume tone. I assume you mean turn up the channel masters, but then lower the volume with the loop master?

 

[Shask]

I agree the effects loop sucks tone (especially low end, some highs too). This is because of a poorly chosen cap value in the stock loop design. I called Mesa about fixing this and Mike B. confirmed there is a loop tone suck mod. I got it done when I had my Rev F recapped last year.

"There is a 2.2uf capacitor connected to pin 3 of tube V4a (which is the effects loop recovery stage). Changing this to a 10uf tantalum capacitor should eliminate the tone suck or at least reduce it substantially. Just be sure to install it in the right direction with the "+" end connected to pin 3. This worked great for me."

I can't guarantee the above replacement value is the same that Mesa used, but that is the cap that they replaced and it makes sense that a higher value would neuter less signal. This mod is more important than transformers or special tubes if anyone here has a serial loop they leave on all the time. Nobody talks about this mod for some reason and just dismiss the loop as being bad.

I am interested in this also. I am now considering opening up my old Rev G 2-channel Triple Recto to see what value this cap is. Looking at the schematic, I can see how this would cut the bass. Maybe this would be worthwhile along with the parallel to serial loop mod.

 

[psychodave]

Personally I think the effects loops on rectos suck tone, but are necessary if you want to get the rectos to sound good at home levels.

I am curious how you use the effects loop to improve the low volume tone. I assume you mean turn up the channel masters, but then lower the volume with the loop master?

I would simply use the loop master as the overall master volume.

 

[D-Rock]

It's an effing G! What are you, some kind of FNG? Lol!

 

[LPMojoGL]

called Mesa about fixing this and Mike B. confirmed there is a loop tone suck mod. I got it done when I had my Rev F recapped last year.

"There is a 2.2uf capacitor connected to pin 3 of tube V4a (which is the effects loop recovery stage). Changing this to a 10uf tantalum capacitor should eliminate the tone suck or at least reduce it substantially. Just be sure to install it in the right direction with the "+" end connected to pin 3. This worked great for me."

I can't guarantee the above replacement value is the same that Mesa used, but that is the cap that they replaced and it makes sense that a higher value would neuter less signal. This mod is more important than transformers or special tubes if anyone here has a serial loop they leave on all the time. Nobody talks about this mod for some reason and just dismiss the loop as being bad.

Ressurected to say thanks.
I'm currently cleaning up an early 1993 Rev F Dual Rec. I noticed the effects loop tone loss, so this info is most appreciated. Man, it's a bitch to get to. Think I'll leave that for someone else to do.:

 

[Snave]

Ressurected to say thanks.
I'm currently cleaning up an early 1993 Rev F Dual Rec. I noticed the effects loop tone loss, so this info is most appreciated. Man, it's a bitch to get to. Think I'll leave that for someone else to do.:

Funny you mention this now. I got my rackmount Dual Recto back from Mesa a few weeks ago after doing this specific mod. Mike B. noted using a higher cap value than the instructions I posted: "Replace the cathode cap at return stage w/ 15 mf for full low end response w/ loop on."

 

[LPMojoGL]

Funny you mention this now. I got my rackmount Dual Recto back from Mesa a few weeks ago after doing this specific mod. Mike B. noted using a higher cap value than the instructions I posted: "Replace the cathode cap at return stage w/ 15 mf for full low end response w/ loop on."

Is Mike B still working on these? Hmmmm.

 

[Snave]

Is Mike B still working on these? Hmmmm.

Yes. Took about 5 weeks.

 

[MaceFremonti]

Had Mike do this mod to both my Trem-O-Verb(and made it serial) and Rev F, substantial difference!