Vintage Marshall-esque Producer

[Tone Taster]

The Amp, simply titled , "Plexi" delivers the truest British Marshall tone I've yet to hear.

 

I've played through the 18W and the 45/50 and couldn't believe that it was really "it"

 

The 45/50 truly combines the JTM w/the Plexi circuit. You can get that deep JTM clean at the lower volumes no prob

 

The power reduction switch on the 45/50 proves most useful for smaller venues

 

This amp will fill up any large venue at 50W.

 

The thing is, is that it is not a clone, but really a fusion of some killer circuits

 

The 18W has a huge variety of the vintage marshall tones by means of the 4 inputs.

 

Their cabinets have a good ambience, too

 

If it looks like I can't afford the two-rock, I may be A/B ing between one of these and my Twin

 

All Point-to-Point to boot

 

check 'em out

http://www.dc-developments.com/plexi_man.htm

 

some ratings:

 

http://www.harmony-central.com/Guitar/Data/DC_Developments/Plexi_18_20_Head-1.html

 

http://www.harmony-central.com/Guitar/Data/DC_Developments/Plexi_45_50_Head-1.html

[miroslav]

A bit too pricey for my tastes!

 

I'm really miffed that something as simple as a tube amp and paper cone speaker combination...

...should cost as much as many of them do!

 

We ain't talking hi-tech or difficult/expensive to manufacture here, guys!

And yet, some of these amp manufacturers really think their selling something "unique" and refined.

[Tone Taster]

Originally posted by miroslav:

A bit too pricey for my tastes!

 

I'm really miffed that something as simple as a tube amp and paper cone speaker combination...

...should cost as much as many of them do!

Wow, then if you were a violinist or a pianist wanting a professional quality bow or even just a baby grand (a Yamaha at that and not even a full Grand) you'd go postal then.

 

I think guitarists complain, bicker, and nitpick way too much as a result of all the cheap crap of substandard quality and price cutting out there when violinists pay 5,000 for a bow or when a pianist pays 10,000 for just a mid grade baby grand.

 

What's a few Grand for a High Quality amp, now?

[Caevan O’Shite]

Caputo- have you tried the 18/20 model? If so, what are your impressions?

 

Miroslav- Well, when you start talking about specifically tweaked reverse-engineered circuits and component choices and values, proprietory custom transformers (VERY expensive for the amp-maker), custom capacitors and/or resistors, hybrid designs combining elements of various classic models along with new tweaks, and very particular attention payed to everything along the way, you ARE selling something very unique and refined!

 

While they may all be paper and metal, all speakers popular for tube-amps are NOT created equal, either!

 

Figure out the parts and design-work and labor it would take YOU to build a production-run of tube-amps, and you'll start to see cost running away on you; I couldn't do it for a reasonable price...

[Dr. Ellwood]

Here is a little interesting insight into a similar situation. I have been with Chrysler Corp. for many years and our resident engineering staff did a supplier inquiry study on what it would take to reproduce a 1968 Dodge factory prepaired 426 dual quad x-ram street capable race car. Original sheetmetal,original engine and power train, electronics, suspension etc. Because of reverse engineering the production systems back to previous capability,materials, foundry reversals in technology, the projected unit cost would exceed $500,000. This also projected to be a strong negative ROI on each unit with no positive bump in marketing efforts as applied to real time current model interest.

[Tone Taster]

Originally posted by Caevan_O'Shite:

[QB] Caputo- have you tried the 18/20 model? If so, what are your impressions?

It's tremendous for blues leads ala 18W bluesbreaker

 

perfect blues amp at 18w.

 

not for pristine clean

[Teahead]

Wow, this must be fate. I arrived at the Cornell site when I spent a few hours searching for ptp UK made amps over the weekend. Since my Vox is out of action again, I wanted something more reliable, preferably more portable and generally better performing.

 

I don't really see myself with the 18w Plexi, but I could definitely live with a 1x12 Vox style Cornell custom.

 

I have a long email about this already written up and waiting to send to a close buddy, but it seems he's one step ahead of me!

 

[miroslav]

Originally posted by Caevan_O'Shite:

Well, when you start talking about specifically tweaked reverse-engineered circuits and component choices and values, proprietory custom transformers (VERY expensive for the amp-maker), custom capacitors and/or resistors, hybrid designs combining elements of various classic models along with new tweaks, and very particular attention payed to everything along the way, you ARE selling something very unique and refined!

 

While they may all be paper and metal, all speakers popular for tube-amps are NOT created equal, either!

Yeah, fine...

...but some of the more sought after "vintage" amps were rather simple designs using inexpensive, non-esoteric components...

.l..and they sounded great.

 

So while it is possible to manufacture expensive, boutique amps...is it really necessary...is that the only way to get a good sounding amp?

 

As far as 200 year old violins and handcrafted instruments like grand pianos...

...they don't quite compare to a tube amp.

[Tone Taster]

Originally posted by miroslav:

 

As far as 200 year old violins and handcrafted instruments like grand pianos...

...they don't quite compare to a tube amp.

True, but if a pro violinist and a pro pianist is going to reflect their very best, they will play with the very best bow or grand.

 

I know your point about the great amps being inexpensive, but alot of those output transformers are hard to find, in addition to alot of research into what can be done to replicate or surpass them due to the scarcity of certain components.

 

You are paying for R&D and quality Craftsmanship. The time it takes to make one point to point amp justifies the expense as well. The 60's compared to today has seen an exponential population boom, so trying to keep up w/demand doing point to point wired amps will justify the cost, too.

 

If you are going to be a pro, play through a pro rig and pay the pro price just like a world class violinist or pianist would. Good thing you're not a B-3 player

[Caevan O’Shite]

Originally posted by miroslav:

"...some of the more sought after "vintage" amps were rather simple designs using inexpensive, non-esoteric components...

O.K., note that the truest, most authentic new reproductions and "reissues" of said "vintage" amps use components that were inexpensive and non-esoteric... a very long time ago... and are now expensive and esoteric in today's world!

 

The designs themselves may be simple by comparison to other electronics, especially now, but their r&d and (especially) proper production is not simple, it's labor intensive all the way. If you figure out all the components that you need for a "tweed" clone, for example, it isn't as simple as soldering everything together and plugging it in. You must slowly bed-in the capacitors to their proper charge, checking and recheckong many steps along the way before you even get to that (a tube-amp must be built in stages, power-supply first and then backwards from speaker-output to instrument-input), test for oscillation and parasitic feedback, accidental bad or mislabeled/wrong-value components (it happens), tweak for final character and tone if you want any consistency from one to another amp as you build them, and on and on and on...

 

If you try to hurriedly assemble them side-stepping some of this, hoping for the best, you'll almost certainly wind up with some amps with smoke or shrieking noises p!$$!ng off your customers...

 

You've got to have all kinds of specialized and sometimes archaic (by today's standards) equipment. Variacs, multiple 'scopes, dummy-loads, signal-generators, DMM's...

 

I can see possibly building even a few tube-amps for myself, but... no way do I perceive ever wanting to go into full-on production, even on a limited scale!

 

"...and they sounded great."

Well, take any given production-model from Fender, Vox, Marshall, etc. from a given time and prouction-run, and some will sound brighter, some darker, some gainier, some cleaner, some tighter, some looser, some louder, and all variations and combinations of these, even when they were brand-spankin' new! So, great was if you found one that suited you to the "nth" degree, and pretty good or good enough was more likely most of the time.

 

Component values generally had a plus-or-minus tolerance-range of 20%... that's up to 40% difference in extremes; these all add up, dictating the final overall characteristics of a given individual tube-amp. Then a slightly shorter or longer wire- OR EVEN THE WAY IT HAPPENS TO LAY- could make not only a perceivable difference in the way the amp sounds, feels, and behaves, but cause critical problems! Ask any tech experienced with vintage Marshalls and Hiwatts... !! (Hiwatts, especially those blessed by the personal touch of one Harry Joyce, enjoy an incredible and rightly-deserved reputation for brilliantly laid-out wiring... !!)

 

"So while it is possible to manufacture expensive, boutique amps...is it really necessary...is that the only way to get a good sounding amp?"

Obviously, NO. I've got a little all-tube Carvin that I'll cart around to jams and people's houses and such- outrageously priced as far as the average non-musician is concerned, even though I got it used for $300, and retubed it for a fair sum- and it does a pretty good job all-around. I get compliments on my tone, and it's the envy of many a solid-state amp player. But I dream with a lusty glaze over my eyes of one day owning a Tone King Comet or Meteor II, pretty pricey Fender-y "boutique" amps, not because of any status-symbol clout, but because I've tried 'em and LOVED 'em. Next in line would probably be either a Fender Vibro King 3x10 or Dual Professional 2x12, also pricey amps that I've found to sound beautiful.

[Teahead]

Compared to the cost of US imports here in the UK, Cornell amps are incredible value for money.

 

Don't forget that these amps are indeed UK built, so the exchange rate makes them look rather less favourable to the US market. One English Pound is equal to around 1.7 of your US Dollars...

 

To add some perspective. I could order the Cornell 18/20 Plexi and a very nice custom cab from those guys for little more than half the cost of a similar Dr.Z head & cab from a UK dealer. The Marshall Handwired 18w is the same price as the Cornell here...no contest really.

 

I suppose the moral of the story is, be appreciative of your own country's plethora of boutique builders and less mournful about those who live in different economies.

[Kramer Ferrington III.]

Originally posted by Caputo:

... if a pro violinist and a pro pianist is going to reflect their very best, they will play with the very best bow or grand.

True enough, but there's nothing to say that bows and grand pianos aren't overpriced as well.

[Tone Taster]

Originally posted by Kramer Ferrington III.:

Originally posted by Caputo:

... if a pro violinist and a pro pianist is going to reflect their very best, they will play with the very best bow or grand.

True enough, but there's nothing to say that bows and grand pianos aren't overpriced as well.

That's why I love a free market. If no one wants to buy it, then it won't sell. If the guy wants to charge a certain price, and people buy it at that price - - great

So overpriced can be relative depending on quality

[LPCustom]

Originally posted by ellwood:

Here is a little interesting insight into a similar situation. I have been with Chrysler Corp. for many years and our resident engineering staff did a supplier inquiry study on what it would take to reproduce a 1968 Dodge factory prepaired 426 dual quad x-ram street capable race car. Original sheetmetal,original engine and power train, electronics, suspension etc. Because of reverse engineering the production systems back to previous capability,materials, foundry reversals in technology, the projected unit cost would exceed $500,000. This also projected to be a strong negative ROI on each unit with no positive bump in marketing efforts as applied to real time current model interest.

Lee, how many units is this for? One? What would the unit cost be for 1000 units? EOS would have to bring the unit cost down to a reasonable level if a production run like that in 1968 was created would it not?

 

Of course, that would probably ruin your CAFE numbers.

 

If I could buy, say, a new replica 1970 Plymouth Road Runner GTX with the 440 and the A727 TorqueFlite from that period, I'd buy it tomorrow. Even if it cost what a modern car costs (easily $35,000). Even if it only got 10 miles to the gallon.

 

I'm thinking that Chrysler couldn't sell these, though because of interference from the Federal Government. They wouldn't meet safety or emissions standards. Or is that part of your equation? To incorporate all the changes to vehicles over the last 35 years into a late 70s muscle car design. I would think that would be a very interesting project. I suppose one factor that would be hard to overcome would be all the additional weight all the new "stuff" would add to the car. That would probably require a very high tech ignition, air and fuel system to get usable gas mileage. (my 1971 383 6-pack RoadRunner got about 12 miles to the gallon -- adding several hundred pounds of safety gear and then adding emissions equipment to it would probably drop that to about 7 or 8, I think)

 

Has Chrysler ever done a study of what it would take to reproduce a vehicle that looks like, say, a 1970 Roadrunner inside and out but is actually a completely new design that incorporates all the advancements over the last 35 years? Obviously it wouldn't look exactly like it. But I think one of those cars updated in design details (reduced wind noise, better suspension, etc.) and technology (fuel injection, electronic ignition, disc brakes) would be a sweet ride.

[LPCustom]

Originally posted by Caputo:

I know your point about the great amps being inexpensive, but alot of those output transformers are hard to find, in addition to alot of research into what can be done to replicate or surpass them due to the scarcity of certain components.

A transformer is nothing more two or more coils of wire over an armature with various tap points into the coils. It is about the most low tech electronic device you can build. If you know how a transformer was wound (how many winds, in what fashion and what gauge wire) they are trivial to reproduce. A manufacturer should be able to reproduce a transformer of their own design quite easily and at minimal cost.

 

The real cost, IMHO, of these reproduction amps is that they are generally built by hand and there is a comparitively small production run so the economies of scale don't really kick in. Since there are few of these amps created, they also charge a premium for them because they are and always will be rare items.

 

On the other hand, new large production run amps from Marshall and Fender cost much more, I think, that they should. And only because they charge whatever the market will bear.

[Tone Taster]

Originally posted by LPCustom:

A transformer is nothing more two or more coils of wire over an armature with various tap points into the coils. It is about the most low tech electronic device you can build. If you know how a transformer was wound (how many winds, in what fashion and what gauge wire) they are trivial to reproduce. A manufacturer should be able to reproduce a transformer of their own design quite easily and at minimal cost.

With all respect justly due to your experience, I wouldn't dismiss the complexities or trivialize the scarcity of knowledge it takes to replicate a transformer.

 

I talked for hours w/an amp engineer from Plexi this Saturday, and I was questioning him about the harshness of my Twin and whether it was the output transformer responsible for this.

 

He said, that yes it is the Output transformer which is accountable for a HUGE % of your tone. I had asked him about how to reverse engineer a 50's Tweed Twin transformer, and he said that this is one of the biggest "black boxes". There are very very few companies who can analyze and replicate transformers, they can come awfully close, though. There are folks who have had the exact schematics for vintage amps, who built them to a tee, but the tone was no where near it.

 

Why? Because there was no info regarding the output transformers and if they had one, it was very tough to get replicated.

 

It can be done, but with greater difficulty than which you state

[LPCustom]

Not really arguing with you, Caputo. You are correct for the most part. But we were talking at cross purposes.

 

You are talking about reverse engineering a transformer which is not the same thing as an OEM reproducing one of their own models at all. Which is what I was talking about.

 

Reverse engineering, to be done correctly would require that the transformer be taken apart winding by winding and that can be quite difficult, generally.

 

To faithfully replicate a transformer, you have to know the type of wire used (copper, aluminum or an alloy), the gauge, how the windings are put in place, the spacing on the armature, the type and shape of iron armature used, the size of armature and then the coating(s) on the wire and whether or not the transformer is resin dipped (potted). All of those things can make a difference.

 

You can think of output transformers in much the same way you do guitar pickups. They don't work the same way, but how they are wound and the configuration of the armature/magnets used can make similar differences in how they sound.

 

The schematic is not the only thing that matters when you build a replica of a vintage tube amp. Sure, the components matter but so does the placement. Tube amps use high A/C voltage and consequently generate magnetic fields that can interfere with the operation of tubes. The heater circuit can interfere with a tube's operation (especially the pre-amp tube).

 

So unless you build an exact replica of a tube amp, it is highly likely it won't sound the same. You need to use components that are pretty close to the original, place the components in the same place in the chassis, wire it the same way as the original including routing the wires and the correct wire type and gauge, and use a similar chassis. The output transformer is only part of the mix. It's an important part to be sure since it's where the output comes out. But it's only part of it.

 

If you put the output transformer too close to the power transformer and/or don't align them 90 degrees from each other, the power transformer can induce noise into the output transformer, too.

 

A tube amplifier is a more complex animal than it appears. And they are a bit more complicated to design and build than SS amps. A well designed and laid out tube amp using exactly the same components as a poorly designed and laid out tube amp will sound better every time.

[Dr. Ellwood]

Originally posted by LPCustom:

Originally posted by ellwood:

Here is a little interesting insight into a similar situation. I have been with Chrysler Corp. for many years and our resident engineering staff did a supplier inquiry study on what it would take to reproduce a 1968 Dodge factory prepaired 426 dual quad x-ram street capable race car. Original sheetmetal,original engine and power train, electronics, suspension etc. Because of reverse engineering the production systems back to previous capability,materials, foundry reversals in technology, the projected unit cost would exceed $500,000. This also projected to be a strong negative ROI on each unit with no positive bump in marketing efforts as applied to real time current model interest.

Lee, how many units is this for? One? What would the unit cost be for 1000 units? EOS would have to bring the unit cost down to a reasonable level if a production run like that in 1968 was created would it not?

 

Of course, that would probably ruin your CAFE numbers.

 

If I could buy, say, a new replica 1970 Plymouth Road Runner GTX with the 440 and the A727 TorqueFlite from that period, I'd buy it tomorrow. Even if it cost what a modern car costs (easily $35,000). Even if it only got 10 miles to the gallon.

 

I'm thinking that Chrysler couldn't sell these, though because of interference from the Federal Government. They wouldn't meet safety or emissions standards. Or is that part of your equation? To incorporate all the changes to vehicles over the last 35 years into a late 70s muscle car design. I would think that would be a very interesting project. I suppose one factor that would be hard to overcome would be all the additional weight all the new "stuff" would add to the car. That would probably require a very high tech ignition, air and fuel system to get usable gas mileage. (my 1971 383 6-pack RoadRunner got about 12 miles to the gallon -- adding several hundred pounds of safety gear and then adding emissions equipment to it would probably drop that to about 7 or 8, I think)

 

Has Chrysler ever done a study of what it would take to reproduce a vehicle that looks like, say, a 1970 Roadrunner inside and out but is actually a completely new design that incorporates all the advancements over the last 35 years? Obviously it wouldn't look exactly like it. But I think one of those cars updated in design details (reduced wind noise, better suspension, etc.) and technology (fuel injection, electronic ignition, disc brakes) would be a sweet ride.

Ok LP, well I get this info second hand because I'm with body engineering (sheet metal guy) but I know that yes the cafe numbers where folded into their study not sure on the impact but I wouldn't be suprised if it where. I'm thinking the unit cost was calculated on 2,500 vehicles to be included in that segment of cafe? The 1970 Roadrunner might now have as much appeal to the general public as what Ford did with the re-release of the mustang body. As much as I love the 70 Roadrunner it most likely would not have wide enough appeal to make an exercise like you suggested viable?

[Tone Taster]

Thanks, LP for a most insightful post.

Much appreciated