Recommendations for a couple of amp projects | Warehouse Guitar Speakers

Recommendations for a couple of amp projects

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Clifford C. McLean
06/08/2019 6:17pm

I am about to commence on a couple of amp build projects. The first is an 18 watt Marshall clone. I will build a 1 x 12 combo cabinet for it using mostly 1/2" walnut plywood and some solid walnut to trim it off. I'm thinking I should go with the 30 watt Reaper. The goal is to get that "baby blues breaker" sound. Will the Reaper get me there or should I go with a different speaker?

The second amp project is a 15 watt Blackface Princeton Reverb. It will go in a solid pine combo cabinet with a lacquer finish. What I haven't decided is whether to make it a 1 x 10 or a 1 x 12 cabinet. I'm just not sure what speaker to go with for this project. I love the G12Q in my Tweed Princeton and Tweed Deluxe amps and, from what I read here, the G10Q is a good match with this circuit. My goal on this one is to have it be the "Princeton Reverb-iest" that it can be. (Maybe a G10A-Q or a G12A-Q?) Anyway, I am open to your suggestions.

FYI, I intended to build just one amp kit. But, that led to speakers and YouTube speaker shootouts and chasing tone. Now I am surrounded by amps and boxes of speakers that didn't quite work out but will be perfect for a future project! Man, I got GAS.

06/09/2019 7:28pm

AFAIK, the early 2x12" JTM45's came with the "Silverback"AlNiCo G12M. It's a less aggressive speaker than a classic Greenback. Scumback probably makes the best remakes if you really want that sound. Considering the reduced bass in a 1x12 cab and the raspy high end of the Marshall 18W, I'd go with either an Invader 50 or Reaper HP. Go with the HP if you lean more towards a G12H than G12M. The HP has more & deeper bass and a slightly smoother high end than the Reaper 30. I also think it's a fuller and sweeter sounding speaker than the current Celest G12H-75 Creamback, and the Invader 50 is better than the current G12M-65.

Not sure about the PR amp speaker. There is no G10Q, but a single 10" Q style cone may be too lacking in bass anyway. I'd think either the G10C or G10A would be good for a single 10". My guess based on the G12C vs G12A is the G10A is less upper-mid aggressive and may have a bit less bass punch. The G10C/S is also less-aggressive than the G10C -- possibly with more bass punch. Weber makes some low-priced low-watt AlNiCo speakers like that as well.

Clifford C. McLean
06/09/2019 11:19pm

Thanks for the feed back on the 18 watt project. I will do some pondering on the Reaper HP. I might also consider building the cabinet somewhat bigger than the 20" x 24" x 9" specs to give the low frequency range a bit more room to breath. I have a Vet 30, a Retro 30, and an ET65 I can try with it, too. I just don't think they are ultimately going to give me what I'm looking for in this build.

I have a 10" Veteran, a G10C, a G12C, a G12C/s, and a Weber 12A125A I can try in the PR build. I don't think the 10" Vet will fill the bill. But, a G10C/S might work. For the most part, I'm just not as familiar as I'd like with 10" speakers vs. 12" speakers in various applications. (FYI, the G10A-Q and G12A-Q reference was my way of continuing to prod/urge WGS to give us some lower wattage American voiced alnico speakers.)

Wm Anderson
06/10/2019 5:10pm


I too had thought about building a Baby Bluesbreaker, and for many reasons decided to build an 18W with dual WGS 10"s, and I'm real happy with it. Here are the postings about it in this group:

If you go the 18W route, I *strongly* suggest you join and spend a couple of months in the group. You need to join the group to get all the secret sauce access and learn a ton about the different variants of 18W. There is a lot of knowledge in that group and you'll get a lot of help. I don't want to dump all of my findings and recommendations about which to build and where to source your parts in this group, so head over there.

In general I prefer separating head and cabinet so I can mix and match and split up the weight when I move them. For example, sometimes I set my H&K Grandmeister 36 on top of this one and connect the dual 10"s into the H&K. But, I had a real itch to build this one and due to the platform it's not that heavy.

Clifford C. McLean
06/10/2019 10:34pm

Thanks. I will definitely check them out.

06/14/2019 1:14am

I'd look up the "AX84" 1x12" cab specs. It's probably the best 1x12" dimension out there, and you can run it partially open, ported or sealed with great results. I'd also consider mounting the speaker 68% offset on the X&Y so the internal reflections won't line up harmonically. 1/2" Pine is apparently an excellent choice. Not sure about Walnut-ply -- may be relatively inert depending on thickness. I'd think you could use less than 1/2" thick, but would get significant midrange resonance at 3/8" that might cause substantial off-axis cancellation.

BTW, Ceriatone sells a 'British Style 18W TMB EF86' kit that might get you closer to a baby Bluesbreaker sound if you don't need the Tremelo. It actually makes more sense to split the first 12AX7, so you can drive the EF86 for a really expressive lead sound, and just use the other channel as a standard Plexi "Treble" channel. That would take some figuring, and you'd probably want an extra gain knob b4 the EF86. I'd consider using all Classictone Iron with one of their kits unless you know something worth spending more for. Meren Iron may be worth it if you want the absolute best.

I'm sure there's a lot of good advice on the 18W forum, but I wouldn't get too caught up in which cap or resistor brands sound better. Most people don't really understand how the sound is affected by different cap or resistor types. My believe is it comes down to how resonant and well-shielded they are. FI, Carbon comp resistors pick up more noise than film types. What some may perceive as more "warmth" is likely just how the increased noise masks higher frequencies. They are also more susceptible to temp changes, and ultimately less reliable. I'd avoid them all together if possible.

I'd just go with the Mallory 150 metal film for signal path caps. They are more linear than the TAD mustards, and are cheaper. You can use more resonant ceramic caps or what not for Bright or Treble tone stack positions if you want more upper-mid screech, but that won't flatter a G12H type speaker. Again, the Reaper HP is a bit smoother than the 30 in that regard. The Invader 50 is smoother than the Green Beret, and with less high end than the Reapers.

Tube choices are to individual taste, but it's good to know how the sound of different brand/types actually differ rather than judge by hearsay within a given circuit. There are some especially good current examples within each brand, but I'd generally avoid tubes that are more muddy and/or resonant when a simple circuit tweak can offer more flexibility to muddy or clear thing up. If you aren't going all NOS, I have some general recommendations I've posted all over these boards that we could discuss more somewhere.

Wm Anderson
06/14/2019 8:50am

"I'm sure there's a lot of good advice on the 18W forum, but I wouldn't get too caught up in which cap or resistor brands sound better. "

My point was if you want to learn about and build an 18W, that's where you go, From trem/TMB/Lite circuits and so on, layouts, grounding techniques and so on, all the info and guidance is there. And will lead you to info at websites like Trinity, etc., etc., etc... It's the core for 18W info...

Kinda like if you want to know about WGS speakers, you come here ;^)

06/14/2019 5:37pm

I did not mean to criticize the idea at all. It makes good sense. I just wanted to offer some guidance b4 getting lost in the various parts recommendations.

Wm Anderson
06/17/2019 8:02pm

I didn't take it that way at all, I knew where you were coming from, and you're right about that...

Clifford C. McLean
06/14/2019 6:33pm

Thanks for all the input on the 18 watt build, everyone.

I think the 18 watt amp build itself is going to be pretty straight forward. I've done a little digging and think I am going to pass on the TMB versions for this particular build. And, I'm not going to get too picky as far as fine tuning the circuit via caps or resistors, etc. (Mainly because I'm just not that sophisticated.)

For the most part, I agree with something Vaughn said relative to the pickups and the speaker being the two biggest things that influence tone. The caveat to that is, of course as far as the amp is concerned, that it also hinges on the amp circuit style and the cabinet that houses the speaker. i.e., a 5E3 circuit amp will sound different in a solid pine cabinet than it will sound in a solid maple cabinet of the same dimensions with the same speaker. And, a 1974 circuit amp will sound different than a 5E3 circuit amp in the same pine cabinet.

The current reissue of this amp has a baltic birch plywood cabinet. I don't like hiding my woodwork with tolex so I'm planning to use walnut plywood on this build.

Basically, my question is, which WGS speaker paired with this circuit (1974) will come closest to replicating the "Baby Bluesbreaker" tone and should the cabinet be altered from stock dimensions (20" H x 24" W x 9" D) to get it closer to that sound?

06/14/2019 7:33pm

By "Baby Bluesbreaker" tone, are you referring to a specific amp, or just the idea of getting an early 2x12" Bluesbreaker amp sound from a 1974X 18W w/1x12 cab? I don't have enough experience or knowledge to answer the first scenario, and my recommendations are only ballpark for the second. Again, I'd assume the first BB speakers were Silverbacks. For WGS I'd try the Invader 50 for a 1x12". Otherwise, Scumback and Weber both make versions of Silverbacks. You'd want a higher wattage version for a 1x12" to have closer bass response as a 2x12". Different watt versions have some variance in high end response as well. I'd choose one with a bit smoother 3~3.5kHz range so it's less piercing up loud. I take SPL graphs of sample clips to try to determine that, and listen to them up loud to confirm my suspicions. Of course that's no guarantee considering the variables involved, but it's the best I can advise.

All I can say is part of what may give a Bluesbreaker combo sound is to use a cab of the same depth as the original. The AX84 cab is just a bit deeper, thinner and shorter than your dimensions, but was designed with a CAD program for a sort of ideal response regarding the cab resonance and certain internal cancellations with a wide range of 12' guitar speakers, but I don't know if that would necessarily be more Bluesbreakery. I can't imagine anyone would be able to answer that definitively. Maybe ask around the web about the AX84 cab, and if anyone recommends about offset mounting the speaker?

Clifford C. McLean
06/14/2019 10:55pm

Thanks for that. The cabinet is going to be a while down the line. It sounds like I need to throw together a baltic birch speaker cab in the original size and try the amp with some of the speakers I have on hand to help develop a point of reference as to what gives me too much of this or not enough of that.

From there, I can pick a speaker and decide if I want to give it a little more room in the final version.

Clifford C. McLean
06/19/2019 6:13pm

From what I can tell from the searching I have done, several different amps have been referred to as Baby Bluesbreakers. In my case I am referring to the Marshall 1974 18 Watt in a 1 x 12 configuration. However, since I am building the cabinet, I could be swayed to do a 2 x 10 cabinet should the proper argument be made. I am not an electrical engineer and never worked in any field that would give me any experience.

This whole amp building thing started as an extension of my woodworking hobby after I retired. But, my ears know what I like and it is a great feeling to finally get the right speaker matched up to a particular amp circuit and cabinet design! (Like my 5E3 amp in a 1 x 12 walnut & cedar cab with the Weber 12A125A or my 5F2-A amp in a 1 x 12 pine cab with the WGS G12Q.)

Up till now, I have mostly stayed with the Tweed circuits. These 2 builds are outside my experience so I thought it prudent to reach out for more information.

Thanks for the responses.

Wm Anderson
06/19/2019 8:43pm

" I could be swayed to do a 2 x 10 cabinet should the proper argument be made."

Per my links, I went to a 2 x 10 over a 2 x 12 due to I figured about 10 pounds due to extra speaker and wood weight. And a 2 x 10 allowed me to get a couple of different voices in the combo vs. just one with a single 12". I found the 10" to be pretty darn nice. In the 70s I had a Marshall 8 x 10 cabinet and it was awesome so I was maybe still a little partial to 10" speakers. I'm really happy with the way it came out.

When all is said and done it comes down to what you want.

I bought an 8" and will say I found a huge drop in sound quality.

Clifford C. McLean
06/20/2019 5:48pm

So Wm, I checked out your pictures. What is the size of your cab? Did you use 5/8" ply for the carcase? Is the baffle board 1/2"?

And, finally, nice job!!!

Wm Anderson
06/20/2019 6:11pm

Yep, It's all 5/8 Baltic Birch except the trim to raise the cloth and the part above that with the control cut out, that's 1/2 Poplar (cheap & reasonable at Menards).

Cabinet is 24 x 20 x 9

06/14/2019 11:41pm

If you leave the cab open at least ~1/3, but not completely open, I think what really matters is the range the reflections from the rear corners and edges cancel. That's why I suggested offset mounting the speaker so all those early reflections are staggered. You can also try gluing foam to the inside rear panels, or just staple a thick towel or fiber pillow over the back of the speaker to eliminate any internal midrange cancellations, but you might find the sound a bit too "dry". I do know the AX84 cab reduces ~800Hz a bit (along with some other slight upper-mid dips and peaks), and has a warm resonance of 140Hz (lower than a typical Marshall 4x12 cab), but those factors along with the port tuning Freq should largely be lost when the cab is at least ~1/3 open. If the dimensions of your cab have shown to work well for what you want, you might just go with it, but there is a pdf of the AX84 cab dimensions you can download here: