# JTM Clubman New 18 Watt Amp With Vintage Parts



## pleximaster

Made this 18 watter for Thomas Hinson (Tom vintage here on the forum)

I made it out of old parts that Tom and I had. Wanted to make the JTM amplifier Marshall never made... 



plexi


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## Guitar-Rocker

Looks like the amp has a 1974 based theme that was started with, and the Normal side changed to JTM? Also looks like a EZ81 rectifier and maybe EL84 output tubes?

Very nice job, by the way !


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## neikeel

Very nice
Looks and sounds very similar to my 18watters, although I can't see what has been done off the board!


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## shakti

Agree, very nice sound. But it appears to be stock 18w into a 4x12, unless there are mods outside the board that we can't see. The old components and transformers is the key here. A good 18w is so fun and effortless to play!


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## pleximaster

Thanks
Its mostly minor value changes here and there, more to get the sound and feeling towards JTM vs JMP
Not so much schematic wise.

Then Tom plays a lot of Stratocaster so I used my Strats a lot in the design and while tweaking it


Originally the idea was to just make an 18 watt clone in head form so you could use different cabs more easily then a combo

It sort of evolved a bit from that and then a lot of trial and testing of different components

Neither of the transformers were the ones originally thought to be used. First MT was changed so it hand be wired for Toms 110 voltage in the US (haven’t tried that yet... ) and the first OT (older version of the RS transformer) was great sounding but had serious “vibrating/singing” issues (core acted like a speaker coil) and I replaced it with this one as singing transformers often turn bad as the coil wiring vibrates agains each other or the coil and insulation breaks

Tremolos have always been an Achilles heal for me when repairing old Marshall’s and I made a few changes. It’s pretty massive perhaps a bit too much for purists...

Plexi


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## Chris4189

pleximaster said:


> Thanks
> Its mostly minor value changes here and there, more to get the sound and feeling towards JTM vs JMP
> Not so much schematic wise.
> 
> Then Tom plays a lot of Stratocaster so I used my Strats a lot in the design and while tweaking it
> 
> Johan joked with me (I am a 98% Les Paul user) and said to me “You tried to designed an amp that makes a Stratocaster sound like a Les Paul...” Probably kind of true!
> 
> We will make a build video on Johan’s channel, Johan Tom and I!
> 
> Originally the idea was to just make an 18 watt clone in head form so you could use different cabs more easily then a combo
> 
> It sort of evolved a bit from that and then a lot of trial and testing of different components
> 
> Neither of the transformers were the ones originally thought to be used. First MT was changed so it hand be wired for Toms 110 voltage in the US (haven’t tried that yet... ) and the first OT (older version of the RS transformer) was great sounding but had serious “vibrating/singing” issues (core acted like a speaker coil) and I replaced it with this one as singing transformers often turn bad as the coil wiring vibrates agains each other or the coil and insulation breaks
> 
> Tremolos have always been an Achilles heal for me when repairing old Marshall’s and I made a few changes. It’s pretty massive perhaps a bit too much for purists...
> 
> Plexi



Schematic or it didn’t happen  I thinks it’s a great sounding amp! Well done sir!


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## tomsvintage

neikeel said:


> Very nice
> Looks and sounds very similar to my 18watters, although I can't see what has been done off the board!





pleximaster said:


> Made this 18 watter for Thomas Hinson (Tom vintage here on the forum)
> 
> I made it out of old parts that Tom and I had. Wanted to make the JTM amplifier Marshall never made...
> 
> 
> 
> plexi



Excellent work pleximaster   !! It sounds just as nice as it looks !! I am looking forward to using this great amp through my alnico loaded 4 x 12 !!


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## shakti

The tremolo on my 18w build (original chassis and OT, old stock parts) has the same hypnotic quality. Very cool tremolo on these even in stock form.


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## neikeel

Over the weekend I will post pics of my 18w Trem head built earlier this year with NOS parts. I am bad because I put a gold block logo on mine. Glad that OT sounds good shakti


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## ricksdisconnected

pleximaster said:


> Made this 18 watter for Thomas Hinson (Tom vintage here on the forum)
> 
> I made it out of old parts that Tom and I had. Wanted to make the JTM amplifier Marshall never made...
> 
> 
> 
> plexi





who is playing?


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## neikeel

ricksdisconnected said:


> who is playing?



It is Johan S isn't it?


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## pleximaster

neikeel said:


> It is Johan S isn't it?


Yes of cause!


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## ricksdisconnected

neikeel said:


> It is Johan S isn't it?




did not know he was a member here.


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## pleximaster

At some points people have had him and me mixed up... 

plexi


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## danfrank

Hi Pleximaster!
I haven't been on here in a while but I just got through Johan's video on this amp... Great job! The amp sound terrific! I think a lot of people will be into this amp because it's a popular size for people to use.
Great work!
I hope you are doing well.


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## ibmorjamn

pleximaster said:


> I don´t know if Johan Segeborn is a member here or not. But we have known each other for years and he has demoed many of my Marshall amps and cabs.
> 
> At some points people have had him and me mixed up...
> 
> plexi


He is a member here , I have not seen him here lately. Nice amp , I am not a Strat player and not in to the tremolo amp but that could be another gain stage instead I suppose right ?


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## pleximaster

Hi Dan!

How are you? We should ha a chat!



About the Marshall Pigs I have another one in the loop of being restored, haven’t finished it (probably had it for the last too years, missing some parts and time, I am also instructed by my doctors not to lift heavy... ) must finish it someday

How are your builds and restorations going?

Plexi



danfrank said:


> Hi Pleximaster!
> I haven't been on here in a while but I just got through Johan's video on this amp... Great job! The amp sound terrific! I think a lot of people will be into this amp because it's a popular size for people to use.
> Great work!
> I hope you are doing well.


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## pleximaster

The Clubman doesn’t have an extra gainstage it actually pretty close to the original. It is more cherrypicked values and selection of parts that are changed.

Plexi




ibmorjamn said:


> He is a member here , I have not seen him here lately. Nice amp , I am not a Strat player and not in to the tremolo amp but that could be another gain stage instead I suppose right ?


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## neikeel

Not hijacking, just sharing the premise:




















Bare chassis and head cab from StevesUK (part in trade). Well made, although I might have had the cab made not quite as tall if I had drawn it up myself. As you see I used correct original RS transformers and NOS parts (apart from the electrolytics). I used the ceramic discs a little more than I would normally and they definitely add some grit and interest when you drive it.
It is, as nearly everyone else claims about a new build, sounding fantastic, just like the clips made by Johan above, and my 2x12 combo. Sounds pretty huge through any of my 4x12s.
Interestingly the little combo it sits on is based on a Ceriatone 18w in a Reason 1x12 cab. I built it with a Scumback G12H55 (Weber era) and it sounded pretty good but I dropped in a G12M modern 16ohm greenback and it has really come alive, maybe because you can drive the amp a little harder with the less efficient speaker. EF86 channel is noisy (despite various tweaks) and, when I get time I will sub a 12AX7 in the previous EF slot, cascade it for SLO type gain and be done.
Pleximasters post and Johan's clips demonstrate how good that first design and build concept by Marshall (pinched from Watkin's??) was.

This is the layout I used:


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## Guitar-Rocker

Fantastic looking build, thank you for sharing the photos.


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## pleximaster

Beautiful built Neikeel as always! I initially started with that same layout! But tweaked it from there. And you are right it is more or less a rip off of Watkins Dominator.



neikeel said:


> Not hijacking, just sharing the premise:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Bare chassis and head cab from StevesUK (part in trade). Well made, although I might have had the cab made not quite as tall if I had drawn it up myself. As you see I used correct original RS transformers and NOS parts (apart from the electrolytics). I used the ceramic discs a little more than I would normally and they definitely add some grit and interest when you drive it.
> It is, as nearly everyone else claims about a new build, sounding fantastic, just like the clips made by Johan above, and my 2x12 combo. Sounds pretty huge through any of my 4x12s.
> Interestingly the little combo it sits on is based on a Ceriatone 18w in a Reason 1x12 cab. I built it with a Scumback G12H55 (Weber era) and it sounded pretty good but I dropped in a G12M modern 16ohm greenback and it has really come alive, maybe because you can drive the amp a little harder with the less efficient speaker. EF86 channel is noisy (despite various tweaks) and, when I get time I will sub a 12AX7 in the previous EF slot, cascade it for SLO type gain and be done.
> Pleximasters post and Johan's clips demonstrate how good that first design and build concept by Marshall (pinched from Watkin's??) was.
> 
> This is the layout I used:


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## tomsvintage

Built by pleximaster with 1960's components and parts





Much thanks and appreciation to my friend pleximaster for all that you do !!!!!!!!


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## South Park

Great tone . I really like that chime sound you get with those el84s with the right gain it sounds great .


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## pleximaster

I have a few projects (Restorations and and builds) going on and while sourcing parts I start new ones...  Here is a new one inspired by the Clubman. This will be a a 18 watt two channel but without tremolo. Will make a similar small head box as for the other Clubman I made for Tom and me (My Clubman is soon done waiting for some parts and valves) Will make Clubman speaker cabs as well

This new Clubman (Custom) I build on an old 63 Concord Linear chassis... Still trying out layout...


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## pleximaster

Will be interesting to see how this one will work out. I have stolen/borrowed many classic designs from all over, however, will they work out together? I am after a compact build at the same time using oversized vintage components (1-2 watt resistors for instance, Ken Fischer supported oversized resistors for tone)

plexi


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## pleximaster

Now I regret not making a schematic and just tried to keep all in my head instead, hard when you pause in a build...

plexi


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## pleximaster

Front

input for the two channels (will be switchable using an external a/b box (less wires inside)

above these are volume and tone for jtm/JMP plexi type of channel 

then there is a wreck like channel with TMB

nfb circuitry build in

I have been inspired by the mhuss T-Rex amp

best plexi


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## pleximaster

I am really keen to know how the Original Concorde Linear Output transformer will work out in this design. It’s a hit or miss I think. You always hear that ultra linear transformers shouldn’t be used in guitar amps. however I got a few early 60 script logo Carlsbro combos and they all are wired using ultra linear options and they sound soo good!


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## pleximaster

update!
As you can see from the long test wirings, I am already rebuilding this one. I finally put in the last wires yesterday but it didn't sound as I wanted it to. Had this great design prepared in my head but reality and hubris hit me and now I have to rethink this one...   

I won´t stop trill it sound good! 

plexi






I might be some miss calculations as I combined two types of preamps, a cathode bias, no choke and ultra linear OT making the voltages off respectively...

...meditate on this I will... (Yoda)


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## pleximaster

Still scratchat my head with this build...

cant get both “preamps” to sound good with the output stage. Either the “plexi” sounds good or the “Fischer” one...

I accidentally sapped myself real good using too many test wires at once and one hit the chassis as I poked around... 

Zzzzzappp! 

Plexi


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## neikeel

pleximaster said:


> Still scratchat my head with this build...
> cant get both “preamps” to sound good with the output stage. Either the “plexi” sounds good or the “Fischer” one...
> I accidentally sapped myself real good using too many test wires at once and one hit the chassis as I poked around...
> Zzzzzappp!
> Plexi


ouch!


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## pleximaster

neikeel said:


> ouch!



Yes Ouch!!!

I think however I am starting to sort things out with different preamp voltages for the two channels. I have to test it out a bit more and then tidy it up. Still have several dangerous long test cables and now the board and pots are hanging in the air!    

Won´t post pictures! What a mess! Haha!


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## pleximaster

In this amp I am trying to built a two channel 20 watt-ish Clubman with one jtm channel and one Fisher/ trainwreck inspired one, where you can go from clean to metal with just the turn of the volume on the guitar. I had a few design flaws (still a few to correct/optimise)

I have change quite a few values from my initial design and this have resulted in temporary long wires that makes the amp noisy at the moment. I also hear a ground loop that I’ll try to eliminate. At the moment I am just glad I got the clean to metal thing going, just using the guitar knobs.

As mention before I build this in a concord linear hifi amp using the OT in ultra linear mode. Guitar is old Les Paul with original PAFs 7.2k 7.8k No high gain pickups.

A good friend of mine thought it reminded of the "Slash tone" and I take that as a compliment!


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## neikeel

Seems to hit most of the necessary spots!


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## tomsvintage

Excellent !!!!


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## shakti

Very cool! What cab/speakers?


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## pleximaster

shakti said:


> Very cool! What cab/speakers?



t652 Celestion alnico!


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## pleximaster

I am making some "Clubman" cabinets for the Clubman and decided to voice them all for Celestion alnicos 

plexi


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## pleximaster

I got rid of the ground loop hum today!  More or less star grounded everything only two points.

Still have some noice but since its a sort of a train wreck design I guess it wound be that quiet... (I never owned a real train wreck but I heard they are not super quiet designs) Any input and experience on this would be appreciated! 

Will make a new sound slip soon (But the kids are off to bed...)

It is really cool on the wreck channel now as you go from totally clean to over the top gain with just the volume control on the guitar.

Not 100 % balance yet between the JTM channel and the Wreck... The JTM preamp section should be go in a bit stronger into the power amp... 

Description
Power amp is inspired by a 1962 Carlsbro CS40 (Ultra linear setup) 
JTM channel is inspired by the 1 watt 50th anniversary JTM1
TrainWreck channel inspired by Trainwreck express and Mark Huss T-Rex amplifier

Built on a Concord Linear amp chassis with old transformers and parts

plexi



plexi


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## pleximaster

I have now put shielded wires to all grids in the preamp, it is very quite now but it has lost some sparkle, I am considering trying to shift and increase some of the upper highs by increasing the values on a few caps but first some tube/valve rolling...

plexi


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## pleximaster

My plan to bulor this neat and clean got flushed down the...

As a prototype project I changed things back and forth so I added new stuff and removed others wires are now all over the place as to reduce noice and hum...

I’ll try to make it a bit tidier though...

However, sound wise it’s a beast and with a bottom shield so quite.


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## pleximaster

Building a 1x12 cab for Tom Hinson today...

also started making a head box for the Clubman Custom chassis I made.

it’s spring and I can be out in the garage and fix stuff!!!


Plexi


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## pleximaster

The clubman classic head box is evolving 

It will be inspired by the Marshall split front 

I reused wood left over from the house I built for the kids rabbits. 

The front is in the second pic laying on top of the Clubman 18 box I made for my 18 watt Clubman

plexi


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## pleximaster

I probably have the notorious virus we all heard about. They don't test here unless you need intensive care. I have however felt rather ill this weekend and had to be in bed all of yesterday. Today however to day I can do some posting on internet...

Here is the splitfront Clubman and its head box.

plexi


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## neikeel

What string are you going to use.


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## pleximaster

neikeel said:


> What string are you going to use.



I will order some reissue string f I can't find any in the basement...  I am not using vintage stuff on this one. The vynair is old but patched together from three smaller pieces... 

plexi


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## pleximaster

Got some more letters for the Clubman logos 

I am waiting for some nice black vinyl/rexcin that Tom has send me to finish these cabs and heads. One of them are only half covered as I ran out. The shipment however is stuck in New York and have been so for some time. Probably due to the horrible Corona crisis there. We all hope and pray for them over there!


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## pleximaster

a bit sloppy playing on a test drive of this other Clubman design I made with vintage parts to be used as a home amp for myself 

this is the trainwreck/AFD Channel straight in. You can get this channel almost clean by just rolling back volume on the guitar. 

the iPhone don’t really capture the sound in clip, 

chassis and transformers are from an old Concord Linear hifi amp


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## shakti

That sounds *really* cool! Love how dynamic it is. What's the speaker cab?


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## pleximaster

shakti said:


> That sounds *really* cool! Love how dynamic it is. What's the speaker cab?



Speaker is an 1962 1x12 Carlsbro PA cabinet with a Celestion Alnico (pushing it I know 12 watt...)

The Dynamic thing is stolen from Ken Fischer designed train wreck 

plexi


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## pleximaster

Finally the amp chassis and back panel is on! 

now I just have to order a custom face plate.

will print some text straps with volume tone an so on for the time being

plexi


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## tomsvintage

pleximaster said:


> Finally the amp chassis and back panel is on!
> 
> now I just have to order a custom face plate.
> 
> will print some text straps with volume tone an so on for the time being
> 
> plexi
> View attachment 75097
> View attachment 75098



Well done my friend !!!!!!


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## pleximaster




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## tomsvintage

Excellent !! What does the feedback switch do ?


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## pleximaster

It a ”precence knob” (NFB) from full to even more!!



Plexi


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## pleximaster

I don´t like to repeat myself making the same design several times so I am already off making another Clubman

It will be a baby hotrodded JTM45, 18 watt version, with 6V6s and will cosmetically be inspired by the Teal amp that was on reverb 1-2 years ago... but with the 19 inches wide cabinet the other Clubmans have. I´ll use old parts and transformers.




Here I am starting out placing parts on the chassis





photoshop idea...


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## pleximaster

There have been some interest from people that wants me to put out a build thread with part lists and layouts. I am working on one and will soon start a three about the Clubman Custom 30


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## pleximaster

This is the Clubman 1x12 speaker cabinet. Tom and I came up with the Clubman concept of doing Marshall inspired design (cosmetically and electronic) but in versions that would suit us better today. They are made of reused parts and should look and smell old... Haha! 







Grey feet




Bass reflector opening to increase Bass respons as the cabinet is made small. (I made this one for Tom H and his Clubman) I´d recommend an old Celestion alnico frame recored with a reissue Celestion Gold cone so it can handle the power in a single 12 speaker. I used wood from an old HiFi speaker and yes it is particle board in the baffle and that is great match sounding for the alnico speaker




The rexin and this gold Fascia Strip comes from Ray D in the US. Looks just great!




Plexi


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## pleximaster

We finally found some teal vinyl for the baby jtm18 that hopefully will match the original jtm45.


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## pleximaster

Clubman 2x12 Teal


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## tomsvintage

pleximaster said:


> This is the Clubman 1x12 speaker cabinet. Tom and I came up with the Clubman concept of doing Marshall inspired design (cosmetically and electronic) but in versions that would suit us better today. They are made of reused parts and should look and smell old... Haha!
> 
> 
> 
> View attachment 76550
> View attachment 76551
> 
> 
> Grey feet
> 
> View attachment 76552
> 
> 
> Bass reflector opening to increase Bass respons as the cabinet is made small. (I made this one for Tom H and his Clubman) I´d recommend an old Celestion alnico frame recored with a reissue Celestion Gold cone so it can handle the power in a single 12 speaker. I used wood from an old HiFi speaker and yes it is particle board in the baffle and that is great match sounding for the alnico speaker
> 
> View attachment 76553
> 
> 
> The rexin and this gold Fascia Strip comes from Ray D in the US. Looks just great!
> 
> View attachment 76554
> 
> 
> Plexi


Amazing work !!!! I will do a video when I get the cab loaded with a nice old Alnico 12 ...I can smell what you are cooking ~ The Teal baby JTM 18 is super cool and I'll be watching the progress on that beauty !!!!


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## tomsvintage

pleximaster said:


> View attachment 76813
> View attachment 76814
> View attachment 76815
> We finally found some teal vinyl for the baby jtm18 that hopefully will match the original jtm45.


Floating in a sea of teal !!


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## pleximaster

Made a first test of the Baby Teal JTM18 head and cab. Its a bit too much gain and a bit muddy yet. Speakers are not the supposed Alnicos that will brighten it up. I will take of some gain off and make the amp also clean up as you roll off the volume on the guitar.

At moment it is fun to play home but won't cut through in a mix and band. 

There is still no back panel on the cabinet that will also tighten up the sound.

Will post the progress of the development of this amp and cab.

plexi

New try out... Now it cleans up rolling up the volume on the guitar...


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## pleximaster

Not all parts in this built will be old but will look old. I found some new strap handles on eBay with nice metal fittings. The actual straps were plastic however so I made some leather straps from an old belt and put in inserts to rise the leather in the middle like tho old ones. colored it with some shoe shine. Many hours spend but super fun!  

One handle will go on the head box and two on the 2x12 Teal Amp.

plexi


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## Guitar-Rocker

I, for one, appreciate seeing the effort of craftsmanship and detail that goes into an amp build. Thank you for sharing. When a hand crafted build looks like it was spit out of a machine, then it's a job well done.


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## pleximaster

At the same time I am Gathering pictures for a build thread and build video of the Clubman 30 that got quite the attention... I am more of building “one offs” but will gladly share when I have the time. I try to improve layouts and such as a first built always have a few prototypes issues.

this is the improved board layout. 

As soon as I get the first amp back (travelling and such Do to Corona have prospond the the return) Neil have said he will help me out making a professional schematics as I don’t have the right computer program 





Plexi


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## pleximaster




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## Amadeus91

^^^^^Pure Class, like the Gentleman who built it!!!!^^^^^^


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## tomsvintage

The Clubman 2x12 Teal combo in all of it's splendor !! Cant wait to hear it again !!!!

Great job pleximaster  Another home run


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## pleximaster

Here is the second Clubman Custom 30 chassis made on an old Concorde Linear 30 hifi amp chassis. Note that the holes for the controls are mirrored on this chassis due to variations of the Concorde amp kit sold in the 60’s

The original OT on this amp was unfortunately broken and I have therefore installed a nice c-core partridge linear OT. It will be interesting to hear the difference between these amps as I tried to keep the other parts and brand parts equal. The MT on this one was a stand up version compared to the first build. Same specs though. 

plexi


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## pleximaster

I replaced a few wires in the Teal Baby Blues JTM45 6V6 yesterday hoping to address some noice and oscillation that sometime occurs when played flat out will everything on 10... finished the work after midnight so I didn't dare test is as the rest of the family was in bed... Hopefully I get some time to test it later... and it pay off. Shield wires in my opinion could sometimes steal a bit shimmer in tone as well as making amps to hifi sounding and smooth. I like the "dirty" untamed sound of regular wires...

plexi


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## pleximaster

Here is a demo of the Teal amp

plexi


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## Joncaster

I just came here from that video! 
First post. 
That tone is crazy great, man. 
I'm busy tuning an amp build of my own (12AU7's into KT77 PSE). searching for the true voice of the circuit, getting ideas.

I would love to see more on this amp!


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## pleximaster

Joncaster said:


> I just came here from that video!
> First post.
> That tone is crazy great, man.
> I'm busy tuning an amp build of my own (12AU7's into KT77 PSE). searching for the true voice of the circuit, getting ideas.
> 
> I would love to see more on this amp!



I just posted this on Johans channel;

_I got a question about the a few of the main factors that influence tone in this amp 

- The design (Based on the classic JTM45 and Bassman) 
- Good quality and vintage transformer RS Heavy Duty OT, RS STD MT, Parmeko choke 
- Oversized resistors mostly Carbon composition 
- RS/Dubillier molded capacitors (my fave even over Mustard caps) 
- Design tweaks (The cleaning up thing, I stole it from Ken Fischer designs) 
- Custom make cabinet, special dimensions and foamed back panel (Less flabby bass) and front portal (pronounced bass response) slightly offset speakers to reduced frequency cancellation
- "Custom made" or custom reconed speakers 
- and the most important one - cool teal color! "_

plexi


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## adew1

Demo sounds great. Amazing amp!


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## pleximaster

I was just informed that Mini Cooper have a "Clubman" with very similar font...  I buy the letters at a place that sells car `pimping" letters... 

I guess I get sued soon!    

plexi


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## tomsvintage

I want to thank pleximaster again for this amazing amp !!!! I plugged it in today through the matching pleximaster built Clubman 1 x 12 cab. I loaded it with a nice Celestion Alnico T 0731.


Videos will follow soon


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## tomsvintage




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## tomsvintage




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