Just built my first tube amp! Custom Dual Rec!

[Anonymous]

Very happy to announce that I've just built my take on the Dual Rectifier!

I'm new to electronics and amp building, but I decided rather than build a typical small Fender or Marshall as a first build, I'd go for something a little "cooler". Basically, I've got a one-channel amp with some options. My Ecstasy does everything I need for most things, but I wanted the classic Rectifier sound, so I build the Red channel. I want to use it as more of a metal amp, so I skipped the Rectifier tubes, but kept a switch to lower the voltages. Adjustable bias and a switch for cutting in and out a negative feedback loop. It was my first build, so everything isn't perfect (have a little extra noise and if I crank the gain, some oscillation), but I'm going to keep at it until that's gone.

How does it sound? Pretty **** good! I'm going to tweak the NFB / presence circuit a little more (I want to have the option of pre-500 tone and possibly SLO territory), but for now, I'd be confident putting it up to the real thing!

 

[Elpelotero]

This is the first in a new line of pre500's. Serial #1. Put some snakeskin on it! When will it be on ebay with a $3,000 buy it now? lol jk! looks awesome!

 

[Anonymous]

This is the first in a new line of pre500's. Serial #1. Put some snakeskin on it! When will it be on ebay with a $3,000 buy it now? lol jk! looks awesome!

Ha! We'll see. My idea is to change parts out until I can start calling it mine! A lot of people boost these amps; I'm thinking about throwing another gain stage in it out front...bright and tight!

 

[Anonymous]

I have a few questions actually. If anyone can answer any of them I'd really appreciate it!

1. Does the input jack connect directly to the V1a grid as the schematics indicate? Or is there a 68k somewhere along the path like every other amp?

2. I see shielded wire in a Recto gut shot going from input to the board, then connecting the gain knob. I didn't have any, but obviously need it. Is there anywhere else besides these two places where shielded wire will really help?

3. The schematics also call for a 1M gain and master pot. I've heard the gain is actually 250k (I used a 1M and there's way too much gain on tap). Any info on the master? Also 250k or 1M as indicated?

4. How much of a difference does the PT really make if it supplies voltage adequately and doesn't overheat?

 

[YellowJacket]

AWESOME!! I was thinking of building a Marshall 18watt Plexi clone this summer.

 

[calvin1]

great job man looks great hope you get it sounding the way you want it to.

 

[Anonymous]

Thanks guys!

So a bit of an update. I took it into GC the other day to put it up to the new Recs. Checked it out next to the Roadster, and **** the Roadster has a lot of bass! Mine seemed to have a lot more gain even on low settings, and although it sounded very good, a few issues started coming up. The biggest problem was that with a lot of bass in my amp, it began oscillating, especially as volume rose. The gain sounded great but it was kind of like something "extra" was in the sound that wasn't pleasant.

Well over the past few hours, I've made a couple of breakthroughs! First off, I've re-routed the grounds using the star grounding technique. Reduced some noise but I still had oscillation issues when banging on the board. Then after much frustration, I realized I missed something in the schematic. I opted for DC preamp tube heaters, but something (apparently) crucial is to connect each bit of the full wave bridge rectifier to ground via 100 and 150 ohm resisters. Problem solved!

The tone now is even better! Very clear, but thick, and with the negative feedback loop engaged, I think I'm getting closer to pre-500 territory! Up next will be getting shielded cable for some important early bits in the circuit. I also need a bias pot, though I'm considering modding the circuit further so I can properly run a pair of unmatched or different type tubes.

To anyone considering trying something like this, I highly recommend it. It can be difficult and frustrating (sourcing the correct parts alone is challenging enough itself), but it's extremely rewarding!

 

[droptrd]

Congrats! Ive been wanting to do something like this for years. I guess I just have to take the plunge. Where did you find a schematic for just the red ch?

 

[iFreedom]

Clips please!

 

[Don]

That's awesome! I built a 5E3 tweed Deluxe clone for a friend last year. I would've never considered something like this as a first build!

 

[rouleau]

WoWW !!!
Congratulation !!

 

[Anonymous]

Congrats! Ive been wanting to do something like this for years. I guess I just have to take the plunge. Where did you find a schematic for just the red ch?

Thanks! I found a Rev. F schematic, then followed which relays would be opened and closed for the Red channel and drew my own schematics. I've got to work a little more with the amp before I can call it finished, though. The schematics from Mesa are definitely wrong in a couple of places, but I need to play and see what will get me closer to true Rectifier tone.

Clips please!

Going to the studio tonight for a session, and will record then. If they're not crap, I'll definitely be posting them!

 

[Anonymous]

So I went to the studio and tested out my revisions with the amp, and **** it's sounding good! I had gain at 9:30, tone controls at noon and presence turned off, and when the MV comes up, hell breaks loose!

I plan on revising a little more so all controls (minus MV) can be run at noon for my favorite sound (plus have a bigger sweep for the preamp presence pot). I also tested out my negative feedback loop (47k tied to the 8ohm jack per Mesa schematics on the Orange channel) and while it recorded well and sounded good, it was a little......boring. I think a little less negative feedback would be great; just enough to tighten up the sound as an alternative to the insanity of the stock Red channel, but not so much that things start feeling choked.

Anyway, I recorded a clip! This is stock a Rectifier sound with the above settings; no negative feedback. Guitar was a friend's Les Paul with an open poled (I think) 498T. The pickup is too close to the strings and that comes through a little. Bogner 4x12 with 65w M75s, with an MD421 close miked, and a Neumann 147 and Royer 121 in M/S config for room. Not too much time spent on placement, but you get the idea. Excuse the noodling!

http://www.soundclick.com/bands/page_songInfo.cfm?bandID=1041631&songID=10467223

Any feedback on the tone is appreciated; good, bad or otherwise.

 

[b0nkersx]

So I went to the studio and tested out my revisions with the amp, and **** it's sounding good! I had gain at 9:30, tone controls at noon and presence turned off, and when the MV comes up, hell breaks loose!

I plan on revising a little more so all controls (minus MV) can be run at noon for my favorite sound (plus have a bigger sweep for the preamp presence pot). I also tested out my negative feedback loop (47k tied to the 8ohm jack per Mesa schematics on the Orange channel) and while it recorded well and sounded good, it was a little......boring. I think a little less negative feedback would be great; just enough to tighten up the sound as an alternative to the insanity of the stock Red channel, but not so much that things start feeling choked.

Anyway, I recorded a clip! This is stock a Rectifier sound with the above settings; no negative feedback. Guitar was a friend's Les Paul with an open poled (I think) 498T. The pickup is too close to the strings and that comes through a little. Bogner 4x12 with 65w M75s, with an MD421 close miked, and a Neumann 147 and Royer 121 in M/S config for room. Not too much time spent on placement, but you get the idea. Excuse the noodling!

http://www.soundclick.com/bands/page_songInfo.cfm?bandID=1041631&songID=10467223

Any feedback on the tone is appreciated; good, bad or otherwise.

That's a lot of gain for only being at 9:30! I think it could used a little bit of presence for the attack, but it sounds great. Really tight and ballsy. It sounds like it's boosted without being boosted, if that makes sense.

 

[lailer75]

**** dude that sounded great. i want one now.

 

[j.d.hall]

Well, I must admit that's bloody impressive! Good work!

 

[boss4]

Very very nice!! My cousin/tech make some very nice amps too:

Marshall P.A.100 (1968/1970(?)) restored by my cousin/tech PJM (best clean sound I've ever heard);
amp without case its a prototype inspired on the marshall plexy but runs two 6L6 + two EL34;
my Dual Rectifier;
on top of the recto is another amp by PJM inspired in the Marshall JCM 2555 but with special extras, like boost and contour.

Smart choice that switch for the negative feedback.

 

[Anonymous]

Thanks again for the feedback!

I've been poking at the circuit over the past few days, and I thing my biggest problem has been in deciding what I want out of the amp. On one hand, I'd love just the stock Rev. G setup. On the other, I want to turn the amp into an ultimate metal Rectifier and just go crazy on it. I've thought of installing a bunch of relays to make my amp capable of switching, but I'm thinking that will get scrapped in favor of simplicity and less noise / circuitry that takes away from the feel.

Anyway, I think I'll be giving a few updates with clips as time goes by.

What kind of changes would you like to see to a Rev. G, if any? I'm thinking I want to make my amp tighter with more gain, while retaining thickness and the voicing that made Rectifiers such a staple.

 

[lailer75]

what kind of $/time do you have invested. i really like your design. a single channel recto w/ no BS

 

[YellowJacket]

How much did the parts cost to build this? Are you going to build more amps now!?