How I build a JTM45 Amplifier. 

It is my pleasure!

Excellent procedure.

OMG, this is how I build my two amps, but didn't want to share it ! There's way too many folks in negative inputs ! However, I found wiring is more enjoyable!

What do you use or like to use for the pt and ot? I want to start my build soon and I have Classic Tone 50 watt for output transformer, I hear they sound nice but I've never got to experience that myself yet. Thanks for the upload.

Jtm45 will be very clean very loud until it’s absolutely cranked and possibly boosted. You probably want a 6knob JCM800

@@TheFunnyzach Thank you , i ended up with a Splawn Quickrod 100, basically a hand wired JCM800 Type amp, with 3 different hot rodded jcm800 voicings, and 2 channels, dual power levels.I love it. I might build a Mojotone or an Ceriatone Marshall head kit as well

Excellent advice as far as compiling individual components go. That’s exactly what I will do. However, there are multiple revision performed to the original circuit design. These are predominantly in the preamp stage and voltage divider sections. I will create more content surrounding these revision.

Excellent catch! I was waiting for someone to notice the voltage value. This particular capacitor is for research use only. I highly recommend that you exceed this value by using only capacitors rated for 630 volts in the phase inverter stage. Very good observation on you’re part.😀

@@FeeserAmplification i see these quite often living in Russia)

Yes. So this design sounds like the mid 1960”s JTM 45. There seems to be a lot of complaints from the owners of the Marshall reissues. Unfortunately the reissues have nothing to do with the originals. For example. The reissues use a duel 50 uF in the power supply filter stage. This not only changes the JTM 45 character but also puts a lot of stress on the tube rectifier.

Yes I agree yours sounds better I don’t think the re-issue sounds that good, It be good if you have them side-by-side demo to compare sounds, there is a company that makes a Rola clone here down under in Adelaide

It's really a 2204

Hot preamp bias or cascaded input

Hello from Eric’s Guitar Amplifier Repair, Believe it or not I get all of my Solen caps from Canada! As far as the paper and oil caps. I Aquire these from Russia through eBay. I can send you the above caps if you just need to mod your personal amp. Just use the link above. My business email is under the contact page and just let me know where to send😄 Cool? Eric-

eBay of course😀

4 eyes 👀 and I still can’t see straight. At least you know that this is truly a hand built JTM45!

@@FeeserAmplification haha no worries, that's what makes it special right?

The red substance is locktight.

@@FeeserAmplification well that was a waste of time. I used the red loctite on my bolts for PT , OT etc. and the stuff doesnt harden, stays liquid for 2 days now. I'm gonna wipe it all off

@@johnmiller9219 Oh my God! So lock tight is a thread locker used specifically for high vibration environments. This is the first time I have heard about lock tight not curing. I have seen some of my colleagues apply there girlfriends nail polish on the fasteners. However. I’m not sure if nail polish will perform a long term hold on the fasteners.

I chose the Black flag Marshall as the original inspiration for the build. Thus I chose the EL34 electron tube.

interesting @@FeeserAmplification

You can get these from me. Just send me the address. If you need a batch then go to eBay😀

Would you feel better if I changed the name?

The Marshall logo is a customer request. Normally all amplifiers that I build carry the Feeser Amplification badge.

@@FeeserAmplification That’s funny, your customer is faking himself! 😂🤣

@@MW47742 Agree....sort of. Lots of people just like to feel the mojo of the original rather than wanting to fake things. I don't do it - it's like Elvis and Beatle impersonators donning bad costumes that insult the originals. Even when I recreate a capacitor, I do not "stuff" - I fabricate a period "style" jacket with differences and label it with the actual capacitor inside. Even that is vanity but a compromise in respecting the vintage while not trying to fake anything or anyone. I'm kind of ok with the Marshall badge here because it emotionally feels good yet is an obvious clone inside. Hopefully the owner doesn't try to re-sell it as an original to the unwary.

Totally 😀

you got that right, I was thinking the same thing the moment I heard the first note played - the rest of the video verified what my ears heard (split cathode, V2A bypass cap) - more like a tube rectified 1987/2204 hybrid. Nothing wrong with that but a completely different beast if you know how a real JTM45 sounds like (even the late '66 transitional ones with the Drake -128 OT running EL34s).

Snubber cap on the cathode follower plate resistor, 33K slope resistor (presumably accompanied by 500pf in treble), different feedback with added "resonance" cap, another snubber in front of the tone stack in parallel to the cathode resistor, no cap on mixing resistor, a voltage divider on it, etc. I can be wrong about something but only one of those things already makes the amplifier different from a JTM45.

Send me the amp and I will take care of everything for you😀

@@FeeserAmplification What's your charge for this? I have the Revision 20 motherboard already.

@@scottdunn2178 www.feeseramplification.com