New Amp Company !

DrBob

Thought you might like a look at this

http://thorntonamplifiers.co.uk/introducing-thornton-dexter/

It's the work of my friend Andy, I'll not say too much more as he explains what it's all about far better than I can, what I will say is guess who's getting Chassis serial number 001 in a head format.

Mwa ha ha ha ha ha

Can't wait, as I'm sure you can imagine I'm very excited, not only because I'm getting a new amp but more because it's amazing to see all of Andys hard work coming to fruition.

ThePrettyDamned

Jealous, sounds like a versatile amp. Would love to hear your thoughts.

ecc83

Yes, very interesting, especially the absence of a standby switch!

"All valve signal path" Can I deduce from that a solid state power rectifier? (hope so!). FX loop to boot. Love to see a schematic but understand there will be little chance. No specific valve line up either.

Seem to be quite a "technical" no BS sort of firm (shame about the "rms" watts but you can't win 'em all!).

I do hope the "finalizing of the remote switching" does not mean they can't quite get it fast or silent enough! If so we could be in for a long wait!

Dave.

DrBob

@ecc83,

I shall direct your questions to Andy & see what he comes back with, in fact I'll direct him to this thread and maybe see if I can cajole him into joining the fold !

ThorntonAmplifiers

Hello All.
DrBob has brought this forum to my attention and it's an honour to join you.
My website is somewhat embryonic at the moment but more detail will be added in the coming weeks.
In answer to ecc83's questions:
The HT rectifier is solid state.  On balance, my personal thoughts are that the pros of valve rectifiers do not outweigh the cons in guitar amplifiers, and I prefer to use a choke to provide some 'sag' in the HT voltage.
Valves used are 4 x ECC83, 1 x ECC82 (LTP phase inverter) and 2 x EL84 (PP cathode biased), but there is an option for a pentode Channel B circuit which uses an EF86 in place of a triode stage.
Sadly, the term 'RMS' has, for so long, been so misused to denote the continuous average power output of audio equipment that it's become ubiquitous.  So many of the world's biggest amplifier manufacturers (guitar and Hi Fi) do this but I know that I shouldn't really perpetuate it, so I'll edit my specifications to state 'average'.
The remote switching (or Pawswitch) is working and the finalising is more about soak/limit testing.  Because I wanted control of all 4 preamplifier modes using 4 dedicated switches with indicators onboard, and using a standard 1/4" 2 pole jack cable (instrument or loudspeaker), the design became a bit 'unusual'.  I want to do a bit more 'testing to destruction'.
Thanks for the questions and comments - I'm looking forward to more discussions.... but I won't be publishing schematics I'm afraid!

Cheers
Andy Thornton

monquixote

How much are they going to retail for?

ElectroDan

Looks great. I bet it sounds pretty good too.

Just a thought, and you can tell me to mind my own business if you like. But the " 'Schizoid' and 'Psycho' modes " names don't seem to fit in with the classy looks/aspirations of the amp. I suppose some people might even be offended.

Good luck with things though, and welcome to the forum. The more amp experts on here, the better.

EricTheWeary

ElectroDan said:

Looks great. I bet it sounds pretty good too.

Just a thought, and you can tell me to mind my own business if you like. But the " 'Schizoid' and 'Psycho' modes " names don't seem to fit in with the classy looks/aspirations of the amp. I suppose some people might even be offended.

Good luck with things though, and welcome to the forum. The more amp experts on here, the better.

I presume they are to fit with the Dexter theme/ name. That's a normal on the outside, crazy on the inside kind of deal.

ThePrettyDamned

EricTheWeary said:

ElectroDan said:

Looks great. I bet it sounds pretty good too.

Just a thought, and you can tell me to mind my own business if you like. But the " 'Schizoid' and 'Psycho' modes " names don't seem to fit in with the classy looks/aspirations of the amp. I suppose some people might even be offended.

Good luck with things though, and welcome to the forum. The more amp experts on here, the better.

I presume they are to fit with the Dexter theme/ name. That's a normal on the outside, crazy on the inside kind of deal.

That was my assumption. 

JookyChap

Oh yeah...the legend is true

jpfamps

ThorntonAmplifiers said:

Hello All.
DrBob has brought this forum to my attention and it's an honour to join you.
My website is somewhat embryonic at the moment but more detail will be added in the coming weeks.
In answer to ecc83's questions:
The HT rectifier is solid state.  On balance, my personal thoughts are that the pros of valve rectifiers do not outweigh the cons in guitar amplifiers, and I prefer to use a choke to provide some 'sag' in the HT voltage.
Valves used are 4 x ECC83, 1 x ECC82 (LTP phase inverter) and 2 x EL84 (PP cathode biased), but there is an option for a pentode Channel B circuit which uses an EF86 in place of a triode stage.
Sadly, the term 'RMS' has, for so long, been so misused to denote the continuous average power output of audio equipment that it's become ubiquitous.  So many of the world's biggest amplifier manufacturers (guitar and Hi Fi) do this but I know that I shouldn't really perpetuate it, so I'll edit my specifications to state 'average'.
The remote switching (or Pawswitch) is working and the finalising is more about soak/limit testing.  Because I wanted control of all 4 preamplifier modes using 4 dedicated switches with indicators onboard, and using a standard 1/4" 2 pole jack cable (instrument or loudspeaker), the design became a bit 'unusual'.  I want to do a bit more 'testing to destruction'.
Thanks for the questions and comments - I'm looking forward to more discussions.... but I won't be publishing schematics I'm afraid!

Cheers
Andy Thornton

Good luck with the amp; it's good to see some designs that aren't copies of the usual suspects.

To be pedantic, putting a choke in the screen supply reduces sag (compared to a resistor).

jpfamps

ecc83 said:

I do hope the "finalizing of the remote switching" does not mean they can't quite get it fast or silent enough! If so we could be in for a long wait!

Dave.

If you use shunt muting switching (either with JFETs or relays) you will have instantaneous and silent switching.

ecc83

Hi Andy!

Thanks for the info. Some guitar amps of my acquaintance use sstate rects and AFAIK have had zero failures. Cannot say the same for the thermionically equipped jobs! Mind you, not having a standby switch would give a valve rect an easier life!

RMS watts? Yeah...Sorry! Bit of a HHorse but I can see why you do it. Don't mind me!

Sag? Maybe you put the choke in the HT line to the anodes? But maybe that is being too nosey? I really don't expect schematics either.

Like to hear the reason for the ECC82 PI. "We" do it to get a low impedance drive and thus can keep opvalve grid leaks lower. (actually the 82 is a driver. PI is done by something else) .

And yes, all the best luck.

Forgot! Whilst I commend your diligence on making a TS jack connected switcher, if I were designing an amp it would have an RJ45 for the remote  (or maybe Bluetooth!!?) since 8 ways makes it easy and there are more places you can buy a CATX patch lead than a jack to jack! Cheaper too!

Dave.

ThorntonAmplifiers

Thank you all for your questions, comments and wishes.
Just a few quick follow-ups:
The Schizoid and Psycho modes are pretty much Series and Parallel channel modes so the 'S' and 'P' initial seemed to fit, whilst suggesting the different 'personalities' that they offer.  No offense intended of course, although I know it's perhaps not very PC!
The 'Dexter' name is actually a tribute to my old mate, a black Labrador who I lost recently, not the US drama killer guy.
Thanks jpfamps for your comments. I'm hoping that my designs will generally offer something a little different.  I'm not really into cloning old classics.
My custom choke has a carefully engineered DCR to add to the tone and dynamic character without compromising punch and response (along with the benefits of HT rail filtering of course).  Hollow state rectifiers tend to have a little too much internal resistance for my liking so solid state plus choke is my preference.
Switching is mainly via gold contact high quality signal relays so it's fast.
The ECC82 PI was the best sounding option I tried while prototyping - seemed to have more 'authority'!
The Pawswitch interconnect was chosen so any old guitar cable will work and there's always some kicking around.  I certainly understand your point re. CAT5 Dave, but it never wants to lay flat on the floor and an RJ45 would feel weird on a valve amplifier!!

Cheers All.

ElectroDan

Looking forward to hearing it.

ecc83

"and an RJ45 would feel weird on a valve amplifier!!"

Dunno why Andy! Amps sport all sorts of connectors these days, 1/8th inch (ugh!) input jacks, USB ports of all shapes and sizes! They put DINs on amps, what a bloody disaster they were!

I worked in the network hardware industry for ten years and became impressed with the RJ45. Once you have the tool they are super quick to fit. The connection regime is very versatile. In addition to data it can carry video, balanced audio (mic signals over FTP) .The plugs are virtually indestructible, can't say that about most audio jacks!

But then Guitarists virtually INVENTED the word "conservative"! (aka intransigent old farts)

And the next thing? Look out for Blackstar's iBeam!

Dave.

Phil_aka_Pip

@ThorntonAmplifiers that looks lovely and welcome to the Fretboard

may I suggest editing "independent" for "independant" /pedantry

not_the_dj

ecc83 said:

And the next thing? Look out for Blackstar's iBeam!

Dave.

Are they getting into structural steel then? 

(is that my coat?)

Cabicular

As a punter I'm with Andy on that one

They are a pain in the arse live unless you tape them to the deck or get a super flexible soft sheath one... ooer

A standard length of cat 5 just doesn't sit right. I've been there with the line 6 floorboards

It's not the end of the world and you can make it work just given a choice I'd rather have a guitar cable or even a midi cable as the Randall Nuno amps do.

Thats just my preference though

Danny1969

We use CAT 5 as the connection from the stage rack to the mixing desk, and to connect ME-1 personal monitor mixers. Anyone who's ever had to set up FOH 75 metres from stage would sing the praise for it. Gotta have the Nuetrik shrouds though. Cat 5 cable designed for gigging is very flexible and cheap

With amps I personally hate the connectors used and the placement. Why do they use 1\4 jacks for speakers and footswitch ..... so you can accidentally plug the footswitch in the speaker socket and short out the OT ........ Here's another thing ...... I've made you this amp that I know your going to be using against the wall in poor lighting conditions (gig) ... so I've put all the connections on the back where you can't see them !!!

One day I'm gonna make my own amp with all the above addressed . I expect it will be ugly as sin and would never sell though

Congrats on your hard work and product though Andy

Cabicular

are you using the X32 stuff Danny?