Single Rectifier Series 1 vs Roadster 2x12 combo - A tale of two amps

[philster]

First Post...

I started my guitar journey some 18 months ago after decades of playing drums and having to quit that due to health reasons. In short order I caught a severe case of GAS and now have a couple Engls, a Marshall, an Orange, a Carvin... and two Boogies, which I'll now introduce:

My first Boogie: a Series 1 50W Single Rectifier. I bought this during COVID (remember?) and am running it through a 412 with 2 x Vintage 30 and 2 x some other Celestion I can't remember. Bottom line is the Lead channel in Modern mode is unbelievable. This is the best guitar sound I've ever heard, period. It is truly orchestral, with so many of what I'd call sympathetic harmonics, huge but tight driving bass, and no annoyance in the fizz department. This amp eats power chords for breakfast! However, the clean channel is not quite there (and I needed a Boogie for the other room) so I went out and bought...

New to the family: a Roadster 2x12 Combo. Rectifier by name, but LoneStar by nature? Certainly, chalk and cheese to the Single Recto. I sit cross legged in front of the Roadster, thing's on bedroom volume, and the channel 1 in clean mode is just divine. Never heard anything like it. This channel makes the most tedious finger excersises pleasurable. To paraphrase a terrible Nicholas Cage... I can pluck a note for hours... Anwyay, where's the recto magic in the drive channels? I've been able to get half-passable Ride the Lightning rythm chugs out of Channel 3. Channel 4, by the manual ostensibly the same as Ch3 seems incurably middy.

And the Roadster seems to have a huge resonance problem in channels 3 and 4 when palm muting chugs on the low E string fretted at C/C#. It's like twice as loud as say palm muted G on or open E. Oddly, C/C# on the A string ain't half as bad. And it's defo not the guitar, as it's doing it with the ibby and the gibbers, neither of which have this issue on any of the other amps.

The timeless conundrum:

Would a multi-watt recto or even a three-channel recto (dual or triple) combine the cleans of the Roadster and the Lead of the Single?

And here a couple pics of my babies.

 

[philster]

"And the Roadster seems to have a huge resonance problem"

No it doesn't. Room placement was all wrong.

Lesson learnt: Don't put the Roadster in a corner!

Strangely, same spot didn't do anything to my Engl (open back) combo...

Got the drive channels sorted as well, just upped the preamp master volume and lowered the output volume. Now it's fantastic on all four channels!

 

[hudakhan]

Wow. Never thought about room placement and it's effects on sound. Good tip.

 

[philster]

Wow. Never thought about room placement and it's effects on sound. Good tip.

Oh I was aware of the importance of room placement just not that different amp / speaker configurations would behave with such variance. The open back Engl Screamer combo (also V30) is perfectly happy in that spot. The Roadster was dismally unhappy. Moved the Roadie by two meters and it sings now!

It’s these many factors that create sound nuances that I love about real amps over simulations, which always sound the same… “too perfect” to my taste

 

[hudakhan]

Agreed. I've tried digital a few times but always sell them. Latest being a headrush. It just doesn't have the same vibe to me. It can sound good but it's just not the same.

I have a roadster that's been with Mesa to get fixed going on a year. I can't wait to get that thing back.

 

[philster]

I have a roadster that's been with Mesa to get fixed going on a year. I can't wait to get that thing back.

Wow. Whats wrong with it? What’s their excuse for taking so long?

 

[hudakhan]

A pop, then channels 2 and 4 don't work. Channel 1 and 2 are both channel 1. Channel 3 and 4 are both channel 3. I live in Alaska. No authorized Mesa repair up here so it had to go back to Mesa. Not sure what is taking so long. Prolly parts. Not enough parts for new amps and repairs would be my guess.

 

[hudakhan]

My mistake. Channels 1 and 3 are both 3. Channels 2 and 4 are both 4. Both of the dirty channels work.

 

[philster]

My mistake. Channels 1 and 3 are both 3. Channels 2 and 4 are both 4. Both of the dirty channels work.

Well, the symptom seems quite drastic, surely they’d be able to identify the cause. Have they told you what went wrong? I’d be keen to know. Mine makes an ungodly crack when flicking to ch3 for the first time like some capacitor unloading into the circuit. Maybe that’s finally got the better of yours? Hope you get it back soon.

 

[hudakhan]

I haven't followed up with them. I shipped in to them in August. I got a call from them shortly after that it was received and in line to get repaired. Richard Duvall at Mesa warned me that it was going to take a while due to parts shortages. I picked up a Mark V 90 shortly after sending that to them, so I got something to work with while it's away but I would really love to have it repaired and shipped back.

Called them while typing this. Bout time to see what the deal is. Talked to Chris in the service dept. Gave him my RMA, asked if this was still in line to get repaired, then he put me on hold to go talk to his tech. Came back and said the tech is going to put that on his bench tomorrow or day after tomorrow and to expect a call in a few days to a week depending on how quickly they can diagnose. Sounds like he prioritized that for me since it's been a while since I sent it in.

 

[hudakhan]

I got my amp back from Mesa. Tested last night and everything works. All channels, all modes. I was kinda bummed because I didn't get any sound on all the channels, but turned out mute was turned on. Sounds great.

It cost me about $200 to ship to them. It cost $155, which included shop time and freight to send back. I was pretty happy about that.

The parts they replaced were:

1x IC 7805 5 volt pos regulator TO-220
1x Jack Mono Stacked
1 hour of shop time @ $110 an hour

Even though it took forever, I'm pretty happy about how all this turned out.

 

[philster]

I got my amp back from Mesa. Tested last night and everything works. All channels, all modes. I was kinda bummed because I didn't get any sound on all the channels, but turned out mute was turned on. Sounds great.

It cost me about $200 to ship to them. It cost $155, which included shop time and freight to send back. I was pretty happy about that.

The parts they replaced were:

1x IC 7805 5 volt pos regulator TO-220
1x Jack Mono Stacked
1 hour of shop time @ $110 an hour

Even though it took forever, I'm pretty happy about how all this turned out.

Took forever indeed! Glad you got it back and it’s working. The cost seems OK, particularly since it was undamaged in transport - always my greatest worry when shipping an amp. For comparison I sent a 6505 from Melbourne to Perth some years back and that cost about US$200 one way.

 

[hudakhan]

Thanks. I'm very happy to have it back. I hear ya on it getting damaged. I didn't have much confidence packing it up with store bought boxes and supplies. Mesa shipped it back in a box with snug, formed foam. Totally secure.

6505 is sick. Peavey is next in my list.

 

[bandit2013]

The multi-channel Dual Rectifiers all have the pop syndrome after you first power it up. It is not just the Rectifiers that have this issue as the Mark V90 Seems to suffer from the same fate. When you first power it up, and if you are using the footswitch, note that all of the LEDs are lit up for all channels. Default is usually CH1. The MWDR does this too but is not as tricky as the Roadster.

Not sure if it is the strobe mute circuit or if it is associated with the method of how Mesa selects channels (it is not a logic chip but an LED driver chip). First thing to do is after you get the amp up and running is to cycle through the channels. It will reset the LEDs and allow for the channels to sync up (basically it is restoring the strobe mute for each channel). Once you do that, it will be noise free.

The difference between the Roadster and MWDR.
MWDR has two identical clone channels, namely CH2 and CH3. Where as the Roadster may appear to have two clones, they are not identical. CH3 is much closer to that of the MWDR and CH4 is a much darker channel. The same could be said for CH1 and CH2 where CH2 has a darker tone to it. Other than the reverb on the Roadster, the MWDR is not that much different except for how the clean channels are designed on the Roadster and where the signal branches off. V1 and V2 are used differently in the Roaster and MWDR. You can do a few tricks with preamp tubes in the Roadster that will not work in the MWDR due to different topography of the preamp circuits.

Yes, CH3 and CH4 will fight you with pinch-off harmonics. The MWDR is a bit more responsive and much easier to get harmonic rips (pinch off notes or taps). I am not using the proper terms though. Sorry I am not well educated in lingo for guitar.

Neat trick to enhance harmonic content, use the tube tracking and spongy mode. Sure this softens up the amp a bit but does enhance the harmonic bliss you can get. Modern, raw or vintage. I normally just use the Modern voice on CH3 and CH4 and spend most of my time on CH4. Not sure why.

The volume difference between Channels 1,2 to Channels 3,4 will be more apparent if you are using the Modern voices. Some say it is because the modern voice disconnects the presence. Not true.
I have studied the schematic and figured out what is going on within the amp. All 4 channels and voices excluding Modern use a fix presence feedback circuit. The controls ill marked as presence are nothing more than a high pass filter and there is no physical or electrical connection to the phase inverter feedback circuit. However, when using modern voices on CH3, CH4, what some misunderstood is correct partly. The fixed presence feedback circuit is disconnected but a different presence feedback circuit is introduced. the Presence controls for CH3, CH4 get reconnected as a true presence control that ties into the phase inverter. It is a very complex and interesting design. So that change in the feedback circuit does add to less negative feedback from the output so the volume will be louder on CH3 and CH4 relative to CH1 and CH2.

One important factor: Know where the cathode followers are located. Not sure about the single channel Rectifier, it may be V3 and V4. The Roadster it is V3 and V5. V3 is the tone stack driver for CH3 and CH4 on the Roaster as well as the single Rectifier. Do not use Russian tubes in V3 or V5 in the Roaster as they will not last very long. Mesa (JJ ECC83s) will perform well. Some Chinese 12AX7 tubes will also do well. They have a flat ribbon wire heater element. Russian tubes use a coiled heater element and for some reason it is the voltage potential between the cathode and heater element that tends to be the issue with cathode follower circuits. Some NOS tubes like the JAN/GE 12AX7WC would be fair game to use there too. The two clean channels on the Roadster have a mark/fender circuit and a plate driven tone stack at the front end of the gain stages.

As for palm muting techniques it becomes more difficult to do when using a 412 cabinet. I get swamped out with sub harmonic content all thanks to the cold clipper circuit used on CH3 and CH4. This is more of an issue when operating at a lower volume setting. You are basically out of the sweet spot at reduced volume levels. It gets much better when you push your hearing tolerances. I have had good luck using a power soak so I can get the amp in the sweet spot and preserve my hearing.

Here is what the Roadster sounds like pushed but using a power soak between the amp and cabinet. I even took some advice on using CH3 in vintage mode, 50W for the lead stuff. That surprised me on the harmonic content. Sorry for the bad drumming skills. I was just learning to use the drums when I did this. Same with the Bass. This was just a one-off test using a multi-track recorder without any rehearsal. Timing is off. Now I play drums in my group when we get together. Even though I started playing the guitar back in 1978. Had given up due to an injury in 2004. So, when I got back into playing guitar, I had to relearn how to play but with a handicap due to the injury.

 

[philster]

Hi Bandit - thanks for the detailed write-up! That track sounds great. Keep up the drumming. If anything, the workout will save you a gym membership...

Is there a self-help group for gear junkies? Anyway, I went out and bought another Roadster, 'cause I found one in good condition for good money and they sound so good. And it came with extra tubes, all of which tested OK after some DeOxit treatment. (Side note: If your tubes are sounding off, they may just need their contacts cleaned!).

Getting this second Roadster gave me an opportunity to fit one with 6L6 (Mesa) and the other with EL34 (winged C). I like both. I was hoping to like one more than the other, but no dice. 6L6 I find more compressed in the mids and looser in the base. EL34 I find tighter bottom end with a more raw midrange. No difference in treble. All EQ settings identical. The amps sound identical when both have 6L6 tubes and the preamp tubes did test out very similar, although one's got all Mesa branded the other all JJ branded 12AX7s.

Then I figured let's see what about that resonance that I reported in the first post, which is present in both Roadsters. So fitted one with vented back panel (picture). This indeed weakens and moves the resonance down to open E. Fabulous. It does also shift the voicing of the amp more into the mid range. I find I can now dial in more bass without the sound getting tubby.

Then I put the closed back back on to finish the raw ply open back ... and I still like it.

This amp is like going to my favourite Italian restaurant and there are 40 dishes on the menu and I like all of them.

Anyway time to stop playing the amp and continue playing the guitar.

 

[tbonesullivan]

Nice! I will admit that I really... really like playing open back cabinets and combos for the most part. Especially playing indoors, for myself, you just get much better sound dispersion.