Marshalls...

[Hewesy]

Hi all, hope everyones keeping well

I've come to the conclusion that I need a Marshall in my life. Most of my heroes play one, others use an MIAB type pedal to add that tone.

I've typically stayed away due to size/wattage but with the new Origin and DSL models this seems a sensible time to look at one.

Trouble is, the "cheaper" modern amps get really mixed reviews. The Origin 20H looks perfect as I'm after more of a Plexi/JTM45 sound but reviews are so knife edge its daft. Same with the DSL20HR, seems to get a kicking just because it has the DSL "My First Marshall" tag.

Anyone tried either, any real world thoughts to share?

Hewesy

[Hewesy]

For context I have a Laney VC30 that I adore but it has that "chime" Vox thing due to the EL84's that you can't get away from. Great drive for the Tom Petty type tone but doesn't get thicker.

Don't get me wrong it is awesome at what it does but I'd like another flavour for the more growly type stuff.

I've tried all manner of drive pedals, MIAB's, revalves, speakers etc but I've realised that it is just the EL84's doing what they do.

Hewesy

[ore_terra]

I do like “small” Marshalls, but mind that without EL34 (the big ones) you dont get the classic tones.

Old 70’s JMP can be found for reasonable prices. And they come with master volume.

[Hewesy]

Thanks, its tempting to go old (and I have an SE100 to help tame volume to a certain extent) but the Origin and DSL are EL34's hence the thought of saving some cost/space if the tones stack up.

Hewesy

[CS70]

The best Marshall sounding amp I've tried recently it's the Mezzabarba M-Zero. Unfortunately it ain't cheap. Fortunately I don't like the Marshall sound too much

But as ore_terra says, an used JCM800 doesn't need costing a fortune? A friend of mine just sold his old one - from the 80s - for some 600 (yes I told him he was being an idiot, but nevertheless..). More recent production years are more affordable (that is, can occasionally be found around the amount he sold his for..). If you want a Marshall, buy a Marshall I'd say..

[Hewesy]

Flicking around seems there are some older eras going for sensible money.

Hmm...

[ef37a]

Have a chat with a guy who goes by the sobriquet of ICBM over at thefretboard.co.uk

He has gigged most of them and serviced almost all of them. Marshalls vary in build quality from BSH to feeble and some marks, some years ,had very fragile output transformers I understand.

Tell him the sort of tone/genre you are interested in and I am sure he will point you in the right direction.

Dave.

[Jack Ruston]

The sweet spot for price vs 'that' sound is probably a late 70's JMP or 80's JCM800...which are more or less the same amp. Be aware that even the 50w is INSANELY loud.

The late 70's JMP had plastic power switches instead of the metal toggles. They are less valuable but have a bit more gain, and are master volume - not that you get that thing if you turn them down.

In terms of that modded marshall high gain thing, I'd look at EVH or Friedman.

J

[Hewesy]

Thanks Jack, interesting point that those amps are less desirable. We're a funny bunch aren't we....

I'm more into the crunch sound e.g. Angus, Paul Weller, Paul Kossoff so the JCM's probably aren't my thing - lovely as the 8/900's are.

Dave, thanks for the tip I'll head over as time allows and see if they can help.

Thanks al,

Hewesy

[ef37a]

Thanks Jack, interesting point that those amps are less desirable. We're a funny bunch aren't we....

I'm more into the crunch sound e.g. Angus, Paul Weller, Paul Kossoff so the JCM's probably aren't my thing - lovely as the 8/900's are.

Dave, thanks for the tip I'll head over as time allows and see if they can help.

Thanks al,

Hewesy

You are most welcome. I know faf that Paul Weller uses a pair of Artisan 30 combos, went da'hn sarf and did the mods.

Mind you he can afford them and has someone else to hump them, 'king heavy. The 15 is virtually the same circuit (with the EF86) but still loud enough for most pub use.

If you can find a used one it will be electrically fine, they never went wrong just got bits broken off so even a really tatty one would be ok.

Oh!! NOT to be confused with the ArtIST 15 and 30 although they are still very good amps and said to be first class pedal platforms.
Dave.

[Hewesy]

Cheers Dave, that's interesting to know. Steve Craddock (long term sideman) uses Artisans so I'm not surprised PW has taken them on too.

Can you share any mod details on them? No worries if not of course.

Actually I was going to ask about the Artist, the 3 new 15w models look interesting. EL34, EL84,and KT88 models aren't they?

Hewesy

[ef37a]

Cheers Dave, that's interesting to know. Steve Craddock (long term sideman) uses Artisans so I'm not surprised PW has taken them on too.

Can you share any mod details on them? No worries if not of course.

Actually I was going to ask about the Artist, the 3 new 15w models look interesting. EL34, EL84,and KT88 models aren't they?

Hewesy

Ah, the mods! VERY early days this was and we found that with certain brands of EL84 they would "redplate" slightly so the common cathode bias resistor* was upped to 120R.

The other mod was to the rectifier circuit but you would have to get Blackstar to do that because I do not have the type codes for the components. You are very unlikely to find an amp that has not been modded. The rect mod was to save the GZ34 (they are not what they were in Mullies day! Though the TAD is pretty good) Bruce, the designer hates standby switches because they stress the rectifier valve but you cannot market a 'classic', hand wired all valve amp without one!

As for the rest of the 'new' range sorry, cannot help been gone from them too long now.

My PERSONAL opinion is that I do not like Single Ended valve amps except for a very cheap practice amp but, they seem to sell and you have to pay the bills!

*10 watt rated and a massive over kill but that is the design philosophy, overengineer stuff so a valve failure does not result in collateral damage.

Example: The first Series One 200 experienced some massive flash over of the KT88s (they are ***t these days) and that dumped well over an amp from the 700V anode supply into the surrounding circuitry. Blew every fuse including the one in the 13A plug. All I found on the circuit board was a rather brown grid stopper resistor but it still read well within tolerance.

Dave.

[Folderol]

Example: The first Series One 200 experienced some massive flash over of the KT88s (they are ***t these days) and that dumped well over an amp from the 700V anode supply into the surrounding circuitry. Blew every fuse including the one in the 13A plug. All I found on the circuit board was a rather brown grid stopper resistor but it still read well within tolerance.

Dave.

They call it defensive design. You know they've taken this to extremes when you see a spark gap across the OP Tx primary

[ef37a]

Example: The first Series One 200 experienced some massive flash over of the KT88s (they are ***t these days) and that dumped well over an amp from the 700V anode supply into the surrounding circuitry. Blew every fuse including the one in the 13A plug. All I found on the circuit board was a rather brown grid stopper resistor but it still read well within tolerance.

Dave.

They call it defensive design. You know they've taken this to extremes when you see a spark gap across the OP Tx primary

Seen it! We had an Avon cosmetics factory and I worked on the PA. One amp was EL31s (yup 6V TV valves) with 1kV on them and top cap freaking anodes! That had spark gaps set in what looked like Paxolin. Bloody thing used a huge slab Selenium rectifier.

Dave.

[adrian_k]

I love reading this sort of thing even though I understand not one word

[Drew Stephenson]

I'm assuming that it's the script for the next Star Trek movie being leaked one phrase at a time...

[ef37a]

I love reading this sort of thing even though I understand not one word

Happy to oblige you Adrian but 95% of the words used are perfectly normal English. If there are things you do not understand and wish to learn I would be happy to attempt an explanation and I am sure Will feels the same?

I for example have a very tenuous grasp of computer matters but it is only by stickiing my head up and asking "stupid" questions that I have managed to improve a little of my understanding...What a good forum is for ?

Dave.

[adrian_k]

Thanks Dave I appreciate the offer. Problem is I don’t even know what question to ask.

It’s worse than that - a few years ago I did an online introductory electronics course. I got over 90%. I even spotted an incorrect answer in the exam. But I can’t apply any of it, and through lack of use have forgotten everything. My brain doesn’t seem to work that way. If it had been more hands on maybe I would have understood more, I don’t know.

Anyway sorry for OT excursion...

[Hewesy]

I love reading this sort of thing even though I understand not one word

Happy to oblige you Adrian but 95% of the words used are perfectly normal English. If there are things you do not understand and wish to learn I would be happy to attempt an explanation and I am sure Will feels the same?

I for example have a very tenuous grasp of computer matters but it is only by stickiing my head up and asking "stupid" questions that I have managed to improve a little of my understanding...What a good forum is for ?

Dave.

Well I happen to be an IT Manager so perhaps some handy translation swaps could be arranged?!

Thanks for the tips on the mods, interesting it would be hard to find something unmodded.

Any thoughts on valve brands offering EQ changes? I keep seeing people suggest x valve offers more treble than y brand, is that likely or are we talking minimal change?

Hewesy

[ef37a]

IT? Oh! I would not waste your time H! I think I have got about as good as I am going to get.

On the "valve EQ/tonal differences"? Very agnostic matey. Yes, people I respect on forums SAY " JJs atr this or that and TADs are shite" but quite honestly I could never hear any difference (but then I am clinically deaf!)

Before you blow a ton on some highly praised 'Cryo' tech reflect upon one fact. I have read reams of statements of how a certain valve has made 'night and day' difference to an amplifier. NEVER with any of those claims has there been a supporting before & after recording. Yes, if you swap a valve for a different type, an 'AY' for an 'AX ' say you might hear some tonal change but that will be because the circuit is now WRONG for that valve and it will not be working at its optimum bias or loading. Also, ad hoc swapping of pre amp valves can lead to smoke!

I was charged at Bs to make an ECC83 changeover device so that two different makes could be instantly compared on the fly. The result was was that a collection of ears of some of the most experience people and players in the industry said "Yes, there is A difference, especially when pushed hard but it is so small that it does not matter. The test was to make sure valve inventory was valid across a couple of brands.

Dave.

[Hewesy]

No worries Dave, offer stands though if useful.

Presumed as much, I have swapped a no name valve for JJ Gold and yes, it was noticeable but then again, I swapped it so can I really say for sure?!

I have swapped 12AX7 for 12AT7 and yes, again noticed a difference but as you say probably due to circuit imbalance vs "improvement".

I was just curious around the whole EQ element - I couldn't see how a valve could roll of treble or boost mids etc.

Hewesy

[ef37a]

" I couldn't see how a valve could roll of treble...."

Ah well now, you see a valve is a 'resistor', the 12 AX7 'looks like' about 60k Ohms and so any capacitors connected with it will form a filter circuit.
The 12AT7 is lower, around 22k iirc and so will change the frequency of those filters but as mentioned, the bias will not be right for an AT7 and so it will probably distort at a lower drive level than the AX7.

When it comes to 'improved' or boutique valves of the same type, then I, as a technician have a problem. Valves are incredibly precisely engineered structures the size and spacing of the electrodes is critical if one is to meet its specification, that is the published papaer parameters. For a circuit to work as designer those parameters must be spot on. Things like the resistance ^ and 'Amplification Factor' or 'mu' (100 for the 12AX7 but you don't get all of that) HAVE to be as published or the valve won't work as required.

Dave.

[Folderol]

I would add a small caveat to Dave's excellent post.
There are two things that might be improved in some designs. The first is improved support structure to reduce microphony, and the other is the routing/shielding of the heaters to reduce hum pickup (although these days world+dog feeds them with DC).

[ef37a]

I would add a small caveat to Dave's excellent post.
There are two things that might be improved in some designs. The first is improved support structure to reduce microphony, and the other is the routing/shielding of the heaters to reduce hum pickup (although these days world+dog feeds them with DC).

Yes, and example of that is the TAD 7025 High Grade. That is ELECTRICALLY identical to the ECC83/12AX7 but of more rigid construction and, I assume, selected for better noise.

It should also be remembered by the cork sniffing guitar amp tweaks that many of these valves were developed for NON audio, or a least not critical quality audio purposes? The 12AT7 is a good example. Originally used in TVs (Google "sync separator") and some hum, distortion and microphonics did not matter a jot!

The 12BAH7 used in a current (superb!) 5 watt amp was also developed for TV and 'scopes and has an anode voltage rating of 2kV pulse!

DC heating? Yes Will, very easy to do now with modern components, regulators and such and really the only way to go for printed circuit design. The latter is frowned upon by the 'Old School' but PCB build is JUST as good a P2P or turret construction, is far more consistent sample to sample and is VASTLY cheaper and that puts excellent designs into the hands of those who could otherwise not afford them.

BTW the 7025 HG is an excellent replacement 12AX7 and, last I looked, not silly money.

Dave.