Real vs replica JTM 45 with APx515
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- Опубликовано: 8 фев 2025
- Within the first few hours analyzing amps with this APx515 I was able to identify tonal characteristics of the block end JTM45 and apply those specs to the replica amp.
This analyzer has the ability to take what I call a "DNA sample" of an amp and save it for future reference. Everything about the signal path, gain, frequency response, clipping, harmonics, distortion... It's mind boggling.
Definitely a game-changer. I have this unit on demo for a short time, so I'll be documenting as many vintage amps as possible and will be saving pennies until I can own one.
SUCH AN EXCEPTIONAL JOB DONE! This is fantastic. It's actually spot on. I keep listening and it's fantastic. No compression and all that. Just open, dynamic and musical.
Most of the time I couldn't hear any difference in the two amps. And never did I hear what I thought was a significant difference. Brilliant stuff.
I wasnt watching the video for a bit and forgot I was listening to two different amps....great work
Harmonics building up in same place in absolutely same circuit. What a great discovery!!! What an expert!!! LOL :))))
Great work George! Ears can definitely trick you...and get tired etc...Good to have an objective baseline.
and after a few years this new amp will sound even better. Very well done.
Damn George that's impressive! I've played one helluva a lot of originals and reissues/boutiques and by jove I think you've got it! During the demo it became clear that one couldn't be differentiated from the other. THAT is unheard of as you know. Well worth the investment in that piece of equipment.
Thanks! If a $9,000 piece of gear gets me that last few percent closer then I'm sold.
Sounds like it to me! Good job George! I'm really considering buying one more amp,and I think the Metroplex is it!
Wow George, you are truly the best amp builder out there.
Jeez !!!!!...............This is amazing !!!..................Well done Georges !
bro...you're a wizard. The sound is identical.
I really appreciate your honest comparisons and insights on your work! Big thumps up for that. But to be honest: I hear a small but noticable difference between the 2 amps. The old one sound a bit more direct while the metro seems a bit less direct (in my words). No matter what: You are doing great work! I will try one of your amps one day.
That's seems to me a fantastic idea!!
George! GREETINGS!!! IT IS SPOT ON AND STELLAR!!!!!! MY KIND OF AMP!!!!
The first stage, mustard dipped- plate capacitor is soooo important to TONE!
Sounds dead on to me! Congrats.
Sounds awesome!
To my ears with quality headphones the Metro had a warmer attack, not as in your face as the original. Blindfolded I would of guess the Metro was the vintage amp. Both are awesome.
the order of harmonics, the way the wavs clip etc is where all the action is. Good to be able to analyze the 'dna' no doubt....regarding this example, i'd try and dial out the upper bass/lower mid s on the clone as the original is leaner in that area. and will have less flub/ as is always the case marshalls shouldnt have any bass and very little upperbass if any imo.
Holy Shit George !
Go George-it's worth chasing the rabbit-love my metro-plex(desert island amp)
Through my headphones, the replica sounds a bit brighter (not necessarily a bad thing), the original a bit warmer with a bit more depth (is that even possible to hear thru 'phones, on a computer, on youtube?). My 2 cents. I always enjoy the tones, replica or original!
glad to know someone believes in objective measurements rather than golden ears....
MrAletube was there an implication of "rather than" rather than "in addition to?"
jrcenina85 exactly like you said
you need both ears and technology aids to get to the point
Your ears can lie to you! And mine have some damage from playing loud music for a living. Some days they only serve me for a matter of minutes before the ringing starts and perception is slewed. Technology is far more reliable and consistent.
:(
Those amps are pretty much identical. Great job! What did you have to change? That GPM looks stock?
Amazing tones. The amps to my ears are identical. Do you share the specs of the tweaks that deviate from a stock JTM45 schematic?
hey George, I am a fan of your work.You seem to be a serious cat in what you do. Let me know where to find your web site. Thanks,Jim.
metropoulos.net
facebook.com/MetropoulosAmplification/
ruclips.net/channel/UCozrHNBWDa39JoZ76XLfvjw
Hi George, I know this question isn't really relevant to your video, but I thought what guy that knows amps inside and out better than you. My problem is that in my rec room at home where I play my amps there seems to be a problem with the only thing that I can think of is dirty AC outlet power. All of my amps sound shrill and fizzy because of this problem. I bought a power conditioner but that doesn't help eradicate the problem. I was thinking of buying a Tripp Lite isolated transformer outlet box like they use in hospitals. Years ago I never had this problem, then one day it appeared and has never gone away. This is not any kind of a ground loop problem. Any advice as to whether one of these Tripp Lite boxes would solve my problem. It's very unusual problem. I even had an electrician in and they couldn't do anything. Need your advice. Thanks Michael Newell from Niagara Falls, Ontario, Canada
He George, what's the sonic advantage of using CC resistors for the B+?
I see so many builders using them when a MF or MOX would be the safer and more logical choice. Other than sexy gut-shot porn, why else would carbon comps be used?
All resistors actually cause distortion (low order) when high voltage is applied. Carbon comps just do it to a far greater extent, so usually the plate resistors are the way to go if you absolutely must have that sound (Fender replicas for example). The node supply resistors are a useless place to put them, they cannot influence the sound, and if builders are using them there then avoid those builders, power supply resistors need to be temperature stable and flame-proof, and carbon comps are as far away from that as possible.
Love it George. Other than the KT 66's, are there major differences between these amps and the metroplex?
Hey, i have a handwired jtm45 with that type of master vloume installed (clone amp) with the .1 coupling caps off the board, how would i go abouts having them back on the board for a more original stock look?
if you don't put any writings we cannot figure out which is playing which, since your feet - clicking to the switch pedal - are hidden
oh yes, I just understand we must look at that LED on that switcher device
Do you still build a Replica Block end KT66 JTM 45? Ive been eyeballing your new Super Plexi, But i am a traditional type guy and mite consider a straight jtm 45 over the super.
Not building those at this time, sorry.
thank you
whats the eq on the amp?
Do you still you use that measuring tool today?
A dead on match.
Game changer for sure. I can't hear a difference