Brit 800 2204 vs 2203 thoughts

[MirrorProfiles]

Another "Oh my!" I am totally intrigued, and haven't found time to hunt down a schematic to see what one of those might be capable of. We need to know this as well @MirrorProfiles.

Need to spend more time with it, but it’s pretty cool. Definitely its own thing, quite different to a 2203, albeit maybe trying to achieve a similar result (Marshall spent a good chunk of time from the late 70’s onwards trying to perfect footswitchable 2 channel amps with a master volume and reverb). Theres some schematics online although some values are hard to read and i’m not sure how accurate it is. I’m sure Marshall will have a more modern schematic in their servicing department. Planning on taking it in for a once over, they’re local and cheap+quick, and especially great with the oddball amps.

What’s odd to me is it’s very much like a cascaded gain version of the 2150 circuit with some value tweaks. But the 1210 appears to be made with the old ST1 board but the 2150 was a smaller board where pots were mounted to it. 2150 chassis had the PI tube between the power amp valves, whereas the 1210 is more like a 2203 chassis

 

[Churchhill]

@MirrorProfiles - Any chance of getting a short clip of your Park? I'd love to hear what it sounds like!

 

[MirrorProfiles]

@MirrorProfiles - Any chance of getting a short clip of your Park? I'd love to hear what it sounds like!

I did this VERY quickly yesterday but will get something proper done soon:

 

[LiamH]

I found the Park 1210 schematic in the back of the Michael Doyle Marshall book. Cute, and one theme that has been endlessly followed by Marshall modifiers quite a bit since. I couldn't believe they had actually fitted a post-PI MV to one of their own production amps all that time ago, and then I found the 2150 schematic... I can see the logic of building the Park 1210 on a "2203 basis", as the circuit topology is very similar. My gut says it's more 2203 than it is 2150, possibly with more shared components. (I think Steve Grindrod maybe modified a 2203 to make the Park prototype, while others were working on Marshall's "next big things".)

Sounds pretty meaty in your short clip @MirrorProfiles! I did at one point have a similar MV arrangement on one of my 2203s, but never really got it sounding how I wanted it to, so went back to standard and used an attenuator when I wanted to avoid making anyone's ears bleed.

Did you get the original footswitch assembly with the amp, @MirrorProfiles? I think I can just about get my head around how it was supposed to work. A bit "Heath Robinson" by modern standards. Having said that, cute idea to make the first stage in the cascade switchable, and some clever lateral thinking using TRS connectors and a 2-core mic cable I would think. It seems you had to plug the guitar into the footswitch, and the footswitch into the high gain input from what I can see on the schematic.

Great thread! Thanks to all that have contributed thoughts, emotions, opinions and knowledge. I don't think we are that far off topic yet.

Liam

 

[MirrorProfiles]

Did you get the original footswitch assembly with the amp, @MirrorProfiles? I think I can just about get my head around how it was supposed to work. A bit "Heath Robinson" by modern standards. Having said that, cute idea to make the first stage in the cascade switchable, and some clever lateral thinking using TRS connectors and a 2-core mic cable I would think. It seems you had to plug the guitar into the footswitch, and the footswitch into the high gain input from what I can see on the schematic.

Didn’t come with a footswitch, by all accounts those are like rocking horse shit these days. Not too hard to build DIY though (although I have no plans to use the amp outside the studio so I have no need). I think you use a TS cable from guitar to footswitch, and then TRS cable from the foot switch to amp. If no cable is plugged into the amp it bypasses the first gain stage, plugging a cable in “activates” the high input, IIRC the JMP2144 had a similar footswitch arrangement to turn the reverb on and off.

It’s an interesting amp for sure, very gainy but quite crunchy too - I guess from the phase inverter being slammed.

The 2150 and Vintage Modern use a similar MV arrangement, the vintage modern sounds best to me maxed out (out the circuit) on the LDR (stock JTM45 mode), but lowering it a bit for the high gain mode can open the tone out a bit and stop it being too bloated. I feel like it’s a similar thing here - MV too low and the tone sounds a bit weak, around midday it’s quite lively and well balanced, going higher changes the tone a lot.

Also curious to try with different speakers. Marshall also experimented with the Park cabs - if you can check out the Park 1008 cab.

V2A seems quite noisy and my stash of quiet valves is running low, so I suspect Marshall will replace when giving it a once over. Filter caps seem to be OK given the age.

A while back I had the 2150 and 1210 schematics side by side. I seem to remember a lot of similarities with the main difference being that the 1210 cascaded channels together (while the 2150 had the 4 hole arrangement).

These 2150 tones aren’t really “typical” of the amp - it wants to be a super lead style amp really, but with a hint more “2203” than something like a vintage modern

(just camera in the room tone)



and boosted (maybe more similar to the cascaded tone):

 

[MirrorProfiles]

oh while I was digging around for more information on Park, I stumbled on these:



Park 1207 IS a 2203 in sheep’s clothing. 1239 is a JMP2144 but with 1x12 rather than 2x12.

I have a 4145 Club and Country here too and that is without doubt one of my favourite Marshalls I’ve ever played. But that’s getting quite far removed from the 2203 lineage….

 

[Churchhill]

oh while I was digging around for more information on Park, I stumbled on these:

First, thanks for posting that clip of your new Park! That thing sounds awesome! To my ears, very much a mix of 2203 and 1959. IDK, but I would agree with @LiamH that Steve Grindrod built this on the 2203 platform, lots of evidence to support that, and a little over-the-top for a typical Marshall at the time, IME.

Those old ads are really cool, too. Late 70s, I presume. So many great things from that period, 2203, 2204, 2104, 2103, 4140, 1987, 1959, those cabs, and those Parks, too, all on the same handful of pages. The Park 1206 looks similar, maybe the same, as the early 2204, basically a 1987 with a master volume.

I need to look up those schematics in the Michael Doyle book, the second edition, wish that was still in print; mine's almost completely worn out. I think I remember something about the 2150 not having a cathode follower in front of the tone stack, but I could be confusing the model. In any case, and especially with the Parks, so many variations on the 2203 and the ideas behind it.

 

[MirrorProfiles]

First, thanks for posting that clip of your new Park! That thing sounds awesome! To my ears, very much a mix of 2203 and 1959. IDK, but I would agree with @LiamH that Steve Grindrod built this on the 2203 platform, lots of evidence to support that, and a little over-the-top for a typical Marshall at the time, IME.

Those old ads are really cool, too. Late 70s, I presume. So many great things from that period, 2203, 2204, 2104, 2103, 4140, 1987, 1959, those cabs, and those Parks, too, all on the same handful of pages. The Park 1206 looks similar, maybe the same, as the early 2204, basically a 1987 with a master volume.

I need to look up those schematics in the Michael Doyle book, the second edition, wish that was still in print; mine's almost completely worn out. I think I remember something about the 2150 not having a cathode follower in front of the tone stack, but I could be confusing the model. In any case, and especially with the Parks, so many variations on the 2203 and the ideas behind it.

Yeah, the 2150 (like the 1210) is plate driven tone stack rather than cathode follower.

I think a lot of these circuits also give clues on where Marshall was headed too - the split channels, master volume, extra gain and reverb were things that were defining features of the 2205/2210 and the Jubilee (albeit no verb).

 

[Churchhill]

Yeah, the 2150 (like the 1210) is plate driven tone stack rather than cathode follower.

I think a lot of these circuits also give clues on where Marshall was headed too - the split channels, master volume, extra gain and reverb were things that were defining features of the 2205/2210 and the Jubilee (albeit no verb).

Exactly. I might add the JCM900 Master Volume Mk.III to that list, too, and then the SL-X. Definitely a lineage there from the 2203.

 

[LiamH]

Yeah, the 2150 (like the 1210) is plate driven tone stack rather than cathode follower.

I think a lot of these circuits also give clues on where Marshall was headed too - the split channels, master volume, extra gain and reverb were things that were defining features of the 2205/2210 and the Jubilee (albeit no verb).

It either was, or wasn't, a great period in Marshall development from my point of view. I traded a Musicman RD-50 110 for a Marshall 4210 (2205 1 x 12 combo essentially), and regretted it from day one. My timing was pretty good, and traded that with a local shop for a 1962 Bluesbreaker Reissue within weeks. The retrograde step continued when I first played a JMP 1986 through a 4x12, and figured it was essentially a 1987 with a bit more bottom end. Still have that one, and I bought (and sold) another BBRI combo since. Not sure how I manage without one! Can't say the same for the 9000 series or JMP-1 that filled some of those gaps. Brilliant I'm sure, but not for me.

In short, Marshall was bright enough to reissue their heritage while trying to establish new models. The developments have been interesting, and have sounded pretty good. At their best, when leaning on rich history of tone, for me that's 1987, 1959, 2203, and 1962 variants. I'd live with adding a 2204 to the list, maybe even a Park 1210!

Liam

 

[MirrorProfiles]

I’m maybe a bit more forgiving.

I think the 8100 is a bit of a classic (it’s on a fair chunk of albums, I could probably name more than I could with a Jubilee or 900).

DSL 100W’s are really great amps in my book. Almost too good for what they cost

I like the JVM, it’s a sign of its success that it’s still in production and it’s a real feat of engineering to offer an amp as complex as something that can be mass produced and not cost a bomb.

The green Astoria was a pretty cool amp, albeit misunderstood.

Vintage Modern is a really cool JTM45 style amp that suffered from a poor marketing campaign and possibly confusing control names.

The 1959/1987/jtm45/2203/2204’s are all classic with good reason though. Can’t say I’m huge on Jubilee’s or 2205/2210’s but they’re part of the story and some classic stuff has been done with them.

I’d love to see more of the oddball and rare stuff modelled, almost for archival purposes. So many of these rare amps end up in the hands of collectors and the majority of people will never get to know what they sound like or how they behave.

 

[Churchhill]

I’d love to see more of the oddball and rare stuff modelled, almost for archival purposes. So many of these rare amps end up in the hands of collectors and the majority of people will never get to know what they sound like or how they behave.

This, right here... x1000. They are all part of the story. For me, understanding how they all fit in helps me understand what the models are capable of, how many of them are related, and how I can use them to the best of my ability.

I would love to see the Park 1210 added as a model! I think it's different enough to deserve inclusion and rare enough that it deserves to be heard. This needs to go into the Wish List, I know.

 

[Smittefar]

This is a great thread guys. Thanks.

I used to own a 2205 (which may or may not have been modded). I thought it was super cool. The normal channel had this bold Marshall clean tone and the drive channel was super raw. The loop and shared master volume were firsts and maybe not the best functioning, but I got it working.
Before that I had the TSL100 where I really liked channel 2. The lead channel was very compressed and the clean channel was only OK, but the rhythm channel has some great rock tones.

Edit: I really wish we had the 2205/2210 in the box as I think they offer something unique. I don't know how close a jubilee is, but that is also supposed to have built-in diode clipping (a built-in rat pedal as my old Marshall guru used to call it.)

 

[LiamH]

@MirrorProfiles and @Smittefar, don't get me wrong, I agree entirely that the DSL and TSL are both fantastic amps. I've had a few occasions where I've needed to borrow either of those from guitar players on the same bill as my band, generally because someone else in my band has failed to bring an amp, or has brought one that won't be any use. (My JMP 1986 converted to 1987 is a cracking bass or keyboard amp, as it turns out.) The TSL100 particularly impressed me with its ability to get in the ballpark of older Marshall amps, while still being its own thing. Loved the DSL too, just not as much as a 1987, 1959 or 2203 in the right (and of course, limited) context for what they do best.

I can't love the 2205/10, and I really have tried. But I used to service a 2210 for a good mate who always got an amazing sound out of it. I know it's more about me and the music I play than anything inherently wrong with the amp.

Do they all need to be modelled? I'm never really sure, as I tend to gravitate to amps that I have used before in the Axe FX. I guess it's my own limitation, in that I know how to make them work for me. When I try amps I'd always dreamed of (Train Wreck, Dumble, etc.) I feel a bit lost in getting them set up for some reason. It doesn't help that the last few amps I tried before I bought my Axe FX II were so consistently disappointing in a live band scenario. This was despite sounding great in the shop, and great when I got them home. One of them was even really promising in the rehearsal studio, but 2 songs into the first gig I realised I wasn't going to be able to love it. (And spent the interval between sets driving home to retrieve one my 2203s!)

I'm probably just a bit too spoilt in having found so many truly great amps that have suited me so well already, and everything but the Matamps (and amps they made for Orange) already modelled in the Axe FX so beautifully, and with really great sounding versions. Everything I really need became available once the 2203 had been added. So on reflection, yes, it would be really nice to have some interesting "oddball" amps modelled for archive purposes as @MirrorProfiles suggests. I'm not entirely sure how FAS would justify it commercially, but then maybe they don't need to, and will be able to send a bit of time for the sake of posterity.

Going back to the Park 1210... I'd be interested to hear from @MirrorProfiles whether the Fractal 2203 model sounds anything like it with the Master Volume moved to the other side of the Phase Inverter? (Haven't deep dived lately, but I'm presuming this might be a possibility). From the schematic, it looks like the 1210 might suffer from the same issue as the later horizontal input JCM 800 2203, in that the PI and preamp tubes are running a little hot on plate voltages. It might always sound a little "brash" unless modified. Pretty much everything else looks like it's aimed at JMP 2203 ballpark, with a little more adjustability when plugged into the high gain input in having control of the middle of the preamp "cascade".

Liam

 

[MirrorProfiles]

Going back to the Park 1210... I'd be interested to hear from @MirrorProfiles whether the Fractal 2203 model sounds anything like it with the Master Volume moved to the other side of the Phase Inverter? (Haven't deep dived lately, but I'm presuming this might be a possibility). From the schematic, it looks like the 1210 might suffer from the same issue as the later horizontal input JCM 800 2203, in that the PI and preamp tubes are running a little hot on plate voltages. It might always sound a little "brash" unless modified. Pretty much everything else looks like it's aimed at JMP 2203 ballpark, with a little more adjustability when plugged into the high gain input in having control of the middle of the preamp "cascade".

I spent a bit more time with it today, the master volume is really reminding me of the 2150 and Vintage Modern. The first part of the taper sounds bad, around halfway it sounds pretty great, between half way and 3/4 it sounds it’s best, and maxed out it’s largely bad (on the VM maxed out works for the classic JTM/plexi sounds but for other tones dropping it a little sounds better to me).

With the JMP2150, I liked setting the MV in the sweet spot that I liked and then ran it with a Fryette Powerstation to actually balance the volume. Not my favourite MV topology because it sacrifices tone unless it’s up loud, in which case, what’s the point? It also makes the presence pot pretty useless (the presence pot in this circuit does almost nothing at all even with the master up).

It’s very fussy on preamp valves, particularly V2, where i’ll probably need to find a new (and quiet) ECC83 to go in there. I wonder if tinkering with dropping resistors or even a variac would have any mileage here?

Balancing the preamp gain controls is by far the most fun aspect of the amp and probably the hardest bit to get right if trying to approximate the tone with the 2203 models. The tone stack is also totally different to a 2203, I’m not sure what plate driven tone stacks are available in Fractal, and which values would come closest. Jubilee is plate driven but quite a different circuit (probably more effective and better designed).

Not that I want to mod it, but the obvious route to take would be to reconfigure the master volume, repurpose V2A and V2B to a gain stage and cathode driven tone stack, and then fine tune from there. The board doesn’t have the Marshall labels on it but pretty sure it’s a straight ST1 so probably easy to do anything with circuit wise.

 

[MirrorProfiles]

Do they all need to be modelled?

I hope that some of these amps are simple enough circuits that adding them wouldn’t be too tricky…. and any quirks that come up may help with modelling more complex amps that may exhibit some of the ideas in these. I’d imagine the main issues would be errors in schematics, component drift, making sure the circuit is factory spec etc.

Some amps are very desirable AND popular/made in big numbers. Others are extremely elusive, but also desirable. Something like a Marshall Major or Park P150 would cost a lot to buy (if you can find one), probably need very careful maintenance/restoration, nice NOS valves, ideally be paired with an appropriate era cab, and it would be unusably loud. Those sort of amps seem like IDEAL candidates to model to me, because almost nothing about the real counterparts is practical in any way.

They actually appeal a little more to me than the having emulations of the most modern amps

 

[LiamH]

The first part of the taper sounds bad, around halfway it sounds pretty great, between half way and 3/4 it sounds it’s best, and maxed out it’s largely bad (on the VM maxed out works for the classic JTM/plexi sounds but for other tones dropping it a little sounds better to me).

That's been my general experience of post-PI MV. Great in theory, and at volume until the power tubes are driven too hard, but the lower end of the range is really unusable. That was the main reason I went back to standard on the 2203 I tried it on and used an attenuator.

It also makes the presence pot pretty useless (the presence pot in this circuit does almost nothing at all even with the master up).

The schematic shows the NFB pick up is at the 4 ohm tap. I guess less NFB to play with has to mean less that the Presence control is able to achieve.

The tone stack is also totally different to a 2203, I’m not sure what plate driven tone stacks are available in Fractal, and which values would come closest.

The topology and values of the stack itself look identical to the 2203 style, but I'd forgotten to check how the 1210's is driven and what it drives. The 2203 is nicely buffered with cathode follower input, and a 1M master volume pot output. I was trying to think what's likely to be in the Axe FX in that style with a plate driven tone stack of similar topology to Marshall. The Hiwatt DR103 (Custom 100) shares some similar ideas, but looks massively "stiffened up" to suit being driven by a gain stage rather than a buffer. Maybe the Hiwatt was a bit more "designed", and a bit less thrown together. Might be worth a try - definitely less dissimilar than the Jubilee too.

I'm not sure why V2 would be too fussy. It's operating with much lower gain than V1 on both sides. Have you checked the plate voltages on the preamp valves? Might just be running very high.

Somehow seems a shame to modify a Park 1210 when they are relatively so thin on the ground. Looking at the schematic it doesn't seem like it would be too hard to convert a horizontal input 2203 into a Park 1210 with some of the mods you are considering. (But even those seem to have rocketed in price!)

Liam

 

[MirrorProfiles]

With both gain knobs all the way down and the master fully cranked, the amp is nice and quiet. With the preamp controls up, the first pot doesn’t change the background noise too much, but the 2nd control gets a bit “pink noise”y as you increase it. Could be something else but I’m not qualified enough to know.

what makes the filter cap arrangement more like a horizontal input 2203? Is it based on where the nodes are situated in the circuit?

Park 1210 has 6 filter caps a la vertical input 2203, horizontal input 2203’s started with 5 and later versions ended up with 3:

 

[LiamH]

what makes the filter cap arrangement more like a horizontal input 2203? Is it based on where the nodes are situated in the circuit?

10k resistor between the cap/choke/cap B+ array and the PI supply in the Park 1210 as with the later 2203s. Earlier 2203 in JMP or JCM 800 form had either 2 x 10k in series initially, and then a 20k 2W on later models. It lowers the voltage on the PI and preamp valve plates substantially. I only learnt about this quite recently, and in this thread. I've only really worked on the earlier 2203s, but it does seem to make the horizontal input models sound harsher.

With both gain knobs all the way down and the master fully cranked, the amp is nice and quiet. With the preamp controls up, the first pot doesn’t change the background noise too much, but the 2nd control gets a bit “pink noise”y as you increase it. Could be something else but I’m not qualified enough to know.

Both the preamp controls go into V1, and between them have quite a bit of cascaded gain. A good and quiet V1, and meticulously clean volume pots will definitely help with that. Good jack socket too, as there is no grid stopper on the high input at V1a. V2 just drives and recovers signal from the tone stack, and doesn't provide a huge amount of gain on either side of it. Unless it's carrying massive plate voltage, it shouldn't be too critical in needing low microphonics, etc.

Park 1210 has 6 filter caps a la vertical input 2203, horizontal input 2203’s started with 5 and later versions ended up with 3:

Yep, so you'd need to find somewhere to put another filter cap or 3 if you wanted to do the conversion. The B+ supply of the 1210 is as "mega filtered" as the vertical input 2203. It has a slightly weird thing, at least compared to a 2203, in that the plates of V2a and V2b will have different supply voltages from one another. I doubt that's a reason for "pink noise" from a less than perfect valve, but I suppose it might be. Only just noticed it, but differs from Marshall filter arrangements I'm familiar with.

Liam