Amp building

[hulakatt]

2) Tweed-style Fender amps have a relatively crowded and cramped chassis, compared to 60's Fender-style amps or most English style amps. A lof of people start on tweed style Fenders so i'm sure its okay but if you want more room to work, the other style kits provide you with that.

Just switching over to British style or BF style chassis is like breathing for the first time!

[Dr Tony Balls]

I just did myself a hypothetical "what would I do if starting today" scenario. Weber still has a lot of good options, and some creative variants but nowhere near what they had when I started. Now a lot of their amps are pretty much the same as what's offered everywhere else. I wandered over to Mojotone, however, and saw their NC3015. Knowing what I know now, and knowing what I prefer, that's got winner written all over it. AC30 style circuit but without the stupid dual chassis and scaled down to 15 watts. Complex enough that you get a lot of amp, but simple enough for a first time build and its got tons of chassis room to play with. I wish they had a 30W version but oh well...

https://www.mojotone.com/British-Style- ... lifier-Kit

[øøøøøøø]

2) Tweed-style Fender amps have a relatively crowded and cramped chassis, compared to 60's Fender-style amps or most English style amps. A lof of people start on tweed style Fenders so i'm sure its okay but if you want more room to work, the other style kits provide you with that.

This is a good point that I'd never really considered.

If you want an ample chassis with plenty of room to work... build a Hiwatt!

[fever606]

Just switching over to British style or BF style chassis is like breathing for the first time!

If you want an ample chassis with plenty of room to work... build a Hiwatt!

Oh yeah, ol’ Dave really left plenty of room to throw your elbows around in there!

Which makes sense, as one of the selling points was servicability.

[hulakatt]

I just did myself a hypothetical "what would I do if starting today" scenario. Weber still has a lot of good options, and some creative variants but nowhere near what they had when I started. Now a lot of their amps are pretty much the same as what's offered everywhere else. I wandered over to Mojotone, however, and saw their NC3015. Knowing what I know now, and knowing what I prefer, that's got winner written all over it. AC30 style circuit but without the stupid dual chassis and scaled down to 15 watts. Complex enough that you get a lot of amp, but simple enough for a first time build and its got tons of chassis room to play with. I wish they had a 30W version but oh well...

https://www.mojotone.com/British-Style- ... lifier-Kit

If they offered that in a 30 watt combo I'd be all over it. Sadly, I just don't like the ac15 near as much as the ac30.

[hulakatt]

If you want an ample chassis with plenty of room to work... build a Hiwatt!

I've been on the fence about building one for too long. No longer! The parts are ordered! I've always wanted a DR504 and I've really been longing for one since I picked up an old Orange ppc412 project cab.

[Dr Tony Balls]

I just did myself a hypothetical "what would I do if starting today" scenario. Weber still has a lot of good options, and some creative variants but nowhere near what they had when I started. Now a lot of their amps are pretty much the same as what's offered everywhere else. I wandered over to Mojotone, however, and saw their NC3015. Knowing what I know now, and knowing what I prefer, that's got winner written all over it. AC30 style circuit but without the stupid dual chassis and scaled down to 15 watts. Complex enough that you get a lot of amp, but simple enough for a first time build and its got tons of chassis room to play with. I wish they had a 30W version but oh well...

https://www.mojotone.com/British-Style- ... lifier-Kit

If they offered that in a 30 watt combo I'd be all over it. Sadly, I just don't like the ac15 near as much as the ac30.

Its the AC30 circuit, just half power. But yeah, 30 watts is nice to have.

[hulakatt]

I just did myself a hypothetical "what would I do if starting today" scenario. Weber still has a lot of good options, and some creative variants but nowhere near what they had when I started. Now a lot of their amps are pretty much the same as what's offered everywhere else. I wandered over to Mojotone, however, and saw their NC3015. Knowing what I know now, and knowing what I prefer, that's got winner written all over it. AC30 style circuit but without the stupid dual chassis and scaled down to 15 watts. Complex enough that you get a lot of amp, but simple enough for a first time build and its got tons of chassis room to play with. I wish they had a 30W version but oh well...

https://www.mojotone.com/British-Style- ... lifier-Kit

If they offered that in a 30 watt combo I'd be all over it. Sadly, I just don't like the ac15 near as much as the ac30.

Its the AC30 circuit, just half power. But yeah, 30 watts is nice to have.

I know but a 15 watt version won't have that same bottom end.

[Dr Tony Balls]

If they offered that in a 30 watt combo I'd be all over it. Sadly, I just don't like the ac15 near as much as the ac30.

Its the AC30 circuit, just half power. But yeah, 30 watts is nice to have.

I know but a 15 watt version won't have that same bottom end.

Care to share the rationale for that? I fail to see how, all things equivalent, a quad of tubes will produce different tone than a pair.

[JackFawkes]

I know but a 15 watt version won't have that same bottom end.

Care to share the rationale for that? I fail to see how, all things equivalent, a quad of tubes will produce different tone than a pair.

I'm curious about that too... If the values of the tone stack portion of the circuit are the same, frequency reproduction in the power amp section will still be virtually identical in a pair versus a quad.
I could maybe see it being a Fletcher–Munson thing? Except the volume difference between 15W and 30W isn't actually very big...
If filtering (tone controls) isn't interfering with the signal, I believe bottom end response should mostly be a function of speaker and cabinet, no?

Jack

[DeathJag]

Bigger transformers sound smoother? I have observed the same, the bigger iron makes it all bigger, whereas the smaller amps sound more lovely. I've been doing things like using a blonde bassman for wet, and a blonde Tremolux for dry. It just doesn't work the other way around.

[hulakatt]

Care to share the rationale for that? I fail to see how, all things equivalent, a quad of tubes will produce different tone than a pair.

True if all things are equivalent but not all things are not between a 15 watt amp and a 30 watt amp, even if they share the same preamp and the bulk of the power amp circuitry.

Is the PT the same size and specs?
Is the OT the same size and specs?
Is the filtering the same?

AC15's typically come in a 1x12 combo cab while the AC30 typically comes in a 2x12 combo cab (or a head and a 2x12 matching cab).

Even if they did use the same PT and OT as the AC30, it wouldn't have the same load and stress on it with only half of the power tubes drawing on them. If you use smaller OT and PT to more properly match the tube set, then the smaller transformer set would give different sound and feel characteristics to the amp. I haven't delved into Voxes very much but I was under the impression that the AC15 and 30 share largely similar but still different preamps and the NC30/15 "corrected" that by using the AC30 preamp with the AC15 poweramp.

[JSett]

AC15's typically come in a 1x12 combo cab while the AC30 typically comes in a 2x12 combo cab (or a head and a 2x12 matching cab).

By bringing cab/speakers into this then you're adding a massive variable and difference.

[Dr Tony Balls]

Care to share the rationale for that? I fail to see how, all things equivalent, a quad of tubes will produce different tone than a pair.

True if all things are equivalent

Alright well that answers my question. Just dont want anyone to get the impression that if you, say, pull two tubes out of your Super Lead you're gonna lose low end or something.

[øøøøøøø]

By bringing cab/speakers into this then you're adding a massive variable and difference.

Regardless of that, she’s 100% right about coils and power supply topologies.

A big stiff power supply versus an underpowered, sagging one can certainly impact low end.

And so, obviously, can the choice of output transformer. You could wind a transformer with the exact same ratio that has way more or less bandwidth depending on primary and secondary inductances, maximum core flux density, etc.

This is a massive variable not only in the bottom end but the top end, too.

And wider-bandwidth transformers were (and are) way harder (and more expensive) to make, so the more expensive the amp, generally the better the transformer it would have.

Full disclosure: I’m not a “vox expert” so I don’t know details about AC15 vs AC30 transformers or power supplies