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JCM25

JCM25


Weight: 4KG


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Review


ckraemer

Very fun kit to build!

This is a very fun some-what ‘pre-built’ tube amplifier kit. The ‘kit’ is two PCBs (one is the component board, and the other is front-panel controls), two decent & beefy transformers (line input power, and high-power audio output), and some miscellaneous HW (like some wires, some resistors, knobs, switches, tube mounts, and 1/4” jacks). You need to supply hook-up wire, the chassis, the tubes (3x AX7 and 2x 6L6, or similar), and a cab! Some electronics know-how is required, and don’t go near those caps when it’s on, close to 400VDC! You need to mechanically assemble the components to the chassis (not supplied), and then re-solder the connections to/from the PCBs. They put pretty big blobs of solder on the connection points, so you just need to get those flowing, and shove in your wires - not too bad! Most connection points are to the component PCB, and just a few shielded-wire signal connections to the front-panel control board. Documentation is mostly very good, and I spent a few weeks studying the schematic and layout diagrams before I fired up my iron! There is a procedure on the web-site that I found after I was ready for testing (oops), but that is marginally helpful. You could probably built it in a few hours if you dedicated the time, but I built it over a few days to prolong the experience.

It was my first tube amp project, and it came out great! Very nice clean tone, and tons of gain! For such a cheap kit, it has a lot of features, like a low-power ‘tri-ode’ mode, treble-mid-bass tone stack, separate gain, volume, and ‘presence’ controls, and a built in effects loop - which is done in a single jack. Needed the recommended steel chassis from the guys on eBay (in the US), and that came pretty quick, but I had to drill some holes to get it to work (component board PCB holes did not line up, no mount spot for output transformer, and no hole for effects-loop jack). Only one minor issue with some power tube resonance in the tri-ode mode when I first turned it on, but that went away when I set the bias pot on the component PCB. I contacted KLD about that, and they were very quick to get back to me about this issue - support was excellent!!

I think this kit is a very good value for the money, and a fun build. It’s got a great clean tone, and gets very loud when you crank it up!

2021/10/8 8:46:58


Nicojvdsf

Surprisingly good sounding amp when built. My Marshall DSL20 is picking up dust now. The only challenge is the chassis. It can cost expensive, especially when shipping internationally, or when building a chassis can be difficult to do right and avoid mistakes and potholes. I used an aluminum case (160mm(D) x85mm(H) x 350mm(W)) and drilled and hacked the right holes into it. The square holes for the transformer, IEC connector, on/off switch and pentode/triode switch are the biggest work. No problem if you got the right tools, but if you don't, I would recommend a third party chassis, like the ones you can order off EBAY from the seller mentioned in the description. I saw a link on this site for them as well, but I would ask for availability first, as they said it is very expensive to express-ship.

The only difference from an actual JCM800, apart from the power stage which is changed to 25W, is the tone stack that is wired Fender style and not Marshall style, though the values of components are the same, and you can hardly hear the difference between the two wirings. It takes away a slight bit of ice-picky treble, and adds slightly more bass when all dials are at 12 o' clock. Can easily be converted to Marshall spec if preferred by consulting both schematics. That's what I did, but the difference was not that big..

I built this amp as a modding platform and it is VERY mod friendly. I put an extra tube in there that can be switched in or out (one of the triodes) to do the #36 mod.

The effects loop as discribed by only one jack is not suitable for low level stompbox effects as the voltage coming out is too high. For a proper effects loop I would recommend the transparent "FX Loop 150" available on this site for a industry standard quality effects loop, which brings the voltage down for the effects pedals, and then boosts it again going back to the power amp section. You wouldn't even know the loop is there when set up correctly.

The transformers are of surprising good quality for the over all price of the kit. The output transformer (25W) even looks exactly like the one on my DSL20 which is slightly over sized for 20W I think which makes sense and it sounds good. The power transformer says "GT30" on it, so I reckon it's a on size for all transformer that is even used in their 30W amps, which means it is definitely up to the job.

Eyelet board is a step down from turret board, but still employs point-to-point wiring, which makes this amp more robust than PCB style builds. The PCB version can also be ordered and is a lot easier to build, which is a trade-off that is well suitable for beginners. The PCB version has thick tracks, and a very direct routing approach which makes it more robust and well performing than many other PCB designs.

Over all, I am very glad that I built this kit. It has that unmistakable JCM800 roar, just on a lower volume of course..

The amp building bug has really bit me now, and I am already planning my next build. Maybe it will even be another KLD..who knows...

2022/1/11 21:57:09


Alex54373

Perfectly good tube amp, to feel the real power of classic British sound!

Good quality of components and their value, good power and sound transformers.

I bought it like a kit for soldering without chassi. Box was fully protected during transportation and came to me in good quality.

All manuals, pictures and resources from site easily help me to build and mount this perfect tube amplifier.

Especially the length of wires from kit and some prepared components from seller side (power transformer wires for 220-230VAC configuration) were pleasantly surprize me.

Seller made everything to help me and understand how to mount this 25W kit.

The logic and way of schematic is also good in this scheme. Many little things which used in amp building are correctly implemented here and i see a good work and quality of product.

Noise level is in good range.

I tried to make some mods but the sound is better in standart scheme.

The board is clear and simple for modifying and repairing.

You can play with type of tubes, their firms and BIAS setups.

Maybe, in future i will add a spring reverb module, to feel more closer to Old School of Rock =)

But now, i fully like my new, good quality, good sounding friend. (I have not the one amplifier, Marshall JCM2000 DSL100 have 50% sound of this amp kit) =)

And chassis, you can do it by your self or can order good quality without any problems and headache from seller!

I like KLD, good amplifiers for best sound!

Good way to make sound more closer to musicians and take it in to the masses!

2022/4/27 4:01:20


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