I Bought My Dream Amp.... TWICE 😳 - JMI Vox AC30 Repair Pt.1

Рет қаралды 1,905

Күн бұрын

I did it! I finally purchased a vintage JMI Vox AC30... well I actually purchased two...
JMI AC30 Playlist: • Vintage JMI Vox AC30
Timestamps:
00:00 - On an adventure!
01:31 - Round 2?!?
02:33 - Not one but TWO AC30's
04:10 - Front - AC30 Super Twin
05:16 - Top - AC30 Super Twin
07:31 - Back - AC30 Super Twin
09:46 - Front - AC30 Combo
10:08 - Top - AC30 Combo
11:17 - Signs of modification
12:02 - Back - AC30 Combo
12:57 - Original Alnico Blue's
13:54 - Side by side
14:18 - On the workbench!
14:41 - Little backstory & why this amp
16:01 - Originality in question
17:34 - Does it work?
18:50 - Weird back cutout
19:11 - Backstory / Matchless connection?
20:48 - The feet...
22:03 - Buy new back panel?
22:45 - Mystery behind missing serial plate
23:48 - Front grill + emblem
25:23 - Crude cutout
27:51 - Chassis removed!
28:32 - What tubes?
30:24 - Whats the circuit's condition?
36:45 - Topboost card
38:08 - The transformers...
39:00 - Power transformer swapped
40:31 - Albion output transformer...?
43:22 - The tone either way?
44:13 - The knobs again
45:03 - Underside reveal
45:49 - OT wire color check
46:37 - Review the remaining components
49:38 - Reviewing the closed back cab
50:08 - Alnico Silvers
51:36 - 444 Recone
52:00 - Original Pulsonic Cone?
53:26 - Impedance
54:01 - Bizarre roller feet
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Пікірлер: 40

@YeatzeeGuitar 10 ай бұрын

Strap yourself in, this is going to be a looooong ride!

@Tonetwisters Күн бұрын

Good on you. I love real AC-30's. Would love to own one!

@12footchain 10 ай бұрын

Congratulations! I literally just bought a 66 AC30 TB gray panel combo this week and am super excited to play the F out of it

@YeatzeeGuitar 10 ай бұрын

Heck ya! Congrats on the new amp!

@BradsGuitarGarage 10 ай бұрын

Jolly good show ol chap! Hold your nerve, these rebuilds are never easy, fast or cheap!

@YeatzeeGuitar 10 ай бұрын

Actively studying your recent project right now!

@joellemaster998 4 ай бұрын

i didnt know the top boost was made with a 12ax7 tube,some enterprising fellow should make a tube top boost pedal! i bet it would sound great with my top hat club royal!

@matthewf1979 10 ай бұрын

What do you mean a ‘64 Twin with JBL’s is heavy? They’re only 92 pounds! I’m sure you looked up the 5963 already, but it’s basically a computer grade 12AU7. I think it’s the vibe/trem tube, so it should matter.

@YeatzeeGuitar 10 ай бұрын

🤣🤣 I can speak to that first hand, Twin with JBL's is insane. No. Thank. You. 😅

@mohamedtlass3842 10 ай бұрын

@@YeatzeeGuitarimagine if you had my super six reverb then!

@YeatzeeGuitar 10 ай бұрын

@@mohamedtlass3842 🫡 I salute you sir, that's a monster.

@mohamedtlass3842 10 ай бұрын

@@YeatzeeGuitar At least it has side handles and wheels!

@Guitar5986 10 ай бұрын

Nice scores! The EL84's probably have gotten so hot that it burned off the tube markings. You will need to pay special attention as these amps typically run EL84's extremely hot. A lot of modern tubes will get eaten alive. For replacements I would look at a quad of TAD EL84-STR Redbase. They are very robust & sound great. Sovtek EL84M are also an option but tonally the TAD's are better imo. I actually have a quad of Telefunken EL84's. Well...one is actually an Amperex. But they don't really work as a quad as there is a 15ish mA swing between all of them. Best I can get from them is running in pairs in not a quad. The TAD's sound good enough that I don't even bother to mess with them. Also, the "nasty looking" caps are likely old Lemco wax coated silver mica's. I think I have a few of these but I haven't bothered to test them for leakage on my Heathkit IT-11. I'll see if I can find them & test for leakage. Given that they are silver mica's they might be fine. But the wax coating is not ideal.

@YeatzeeGuitar 10 ай бұрын

Good point on the EL84's! I've got a quad of matched JJ's in the stash that I was planning to try if these end up being poor tubes. Good call on those nasty caps too! I mean if they work great, but boy are they gross lol

@mohamedtlass3842 10 ай бұрын

@@YeatzeeGuitarthis is one amp that it is worth to go all NOS or at least ANOS

@Guitar5986 10 ай бұрын

@@YeatzeeGuitar Just tested the Lemco wax coated silver mica's I have. I would not be concerned at all about these. Not only do they not leak anywhere from 3-400VDC but they test like a new capacitor. The capacitance value may have drifted slightly but they are rock solid. One of mine is in horrible shape. Mangled leads & it almost looks like it is coming apart. I certainly wouldn't use it because it's too physically unstable but it tests like a brand new capacitor.

@YeatzeeGuitar 10 ай бұрын

@@Guitar5986 rad!

@IAmChrisR 10 ай бұрын

Once you've got both up and running, you should consider doing some TONEX profiles of the amps at various settings. May help you recoup some of the costs! You've got some other cool amps too! #JustSayin'

@YeatzeeGuitar 10 ай бұрын

Haha man there's a sea of people with profiles of every amp I own already. I dabbled in that world with the Kemper, but it's 10x crazier now that everyone and their mom is capturing. I just sold my Kemper, still have my QC. I capture for my own personal use now and don't bother with that rat race. They'll pay for themselves in other ways 🙂

@cpk313 10 ай бұрын

Man @29:31 dude did you dirty on those tubes. The 5963 GE is a crap sounding12AU7 sub and the rest💩. Mullard rectifier is the NOS tube to splurge on.

@YeatzeeGuitar 10 ай бұрын

Really? I would think the rectifier wouldn't matter all that much since it doesn't sit in the audio path.

@ScottyBrockway 10 ай бұрын

@@YeatzeeGuitar Modern ones aren't exactly made as well as those old Mullards, if it ain't broke, don't fix it.

@mohamedtlass3842 10 ай бұрын

@@YeatzeeGuitarjust because something doesn’t sit in the audio path doesn’t mean it won’t affect sound indirectly. Just a few volts difference from your wall or brown box can make a large difference, imagine the rectifier which sags a certain way depending how the amp is pushed.

@YeatzeeGuitar 10 ай бұрын

@@mohamedtlass3842 that's fair, though I have in the past tested with my variac one of my amps with 120 vs 115v and noticed no real difference in sound. I had heard from some the brown box dramatically changed the tone, but I didn't really experience that. Fwiw I do have both mullard GZ34 and an amperex bugle boy GZ34 in other amps, so I can always give it a try.

@pharmerdavid1432 Ай бұрын

@@YeatzeeGuitar I'm just a novice noodle, but have a brown box and researched it a bit, supposedly it effects the tone on tube amps using smaller 6V6 and EL84 power tubes, not much with the larger 6L6, EL34, etc...

@ebeep 10 ай бұрын

Super Twin is '64. Why? Corner protectors but with copper panel and brown grill.

@YeatzeeGuitar 10 ай бұрын

Awesome insight! The tolex and corners perfectly match my '64 AC10 so checks out! Interesting on the vox logo, the ac10 has no line between the letters but both of these do.

@BushidoPhoto 23 күн бұрын

The grille cloth looks totally different as well.

@YeatzeeGuitar 23 күн бұрын

I think the combos might have been replaced

@BushidoPhoto 22 күн бұрын

@@YeatzeeGuitar Love the content, I watched all of the way through. I've owned a few VOX AC-30's, head and combo's as well as some later 70's or 80's solid state amps from them. I love watching videos of people willing to bring them back to life. My current amp is a Magnate panoramic stereo as well as a Quilter tone block 202. My current and only Vox amp is a mini super Beatle just for fun in the living room. I can't wait to see this project come to a conclusion. I sub'd to your channel as well. Cheers!

@YeatzeeGuitar 22 күн бұрын

@@BushidoPhoto That's awesome! Lots of videos in this series, but if you want to get straight to hearing it in action I just posted a video a few days ago of me using it live 😎

@J.C... 10 ай бұрын

444 is supposed to be a 55Hz cone vs 75Hz for a 1777 code.

@YeatzeeGuitar 10 ай бұрын

Interesting! Kind of cool actually, now I'm really curious how the two original blues sound in the ST cab next to this silver pair.

@richardcray2919 10 ай бұрын

1777 is the production code for this speaker..nothing to do with the cone..the 003 and 444 is to do with the cone..go to bygone tones and its explained there in detail..all you ever need to know about old celestions.

@J.C... 10 ай бұрын

People modify amps because theyre 10 yrs old and nobody's worried about how much it'll be worth in 60 years. They mod it because it's a tool to be used just like a wrench or a hammer. I don't understand why so many people ask that question about older equipment. "why would someone do this?" you know exactly why. Because at the time, it was just a $600 amp. Not everybody is a collector nor are they worried about what a collector might think in 60 years. 🤷 I mean... It's the same reason every time, no matter the equipment.

@YeatzeeGuitar 10 ай бұрын

Well it's one thing to mod something, it's another to take the time / care to mod it well. My '63 LP junior is a good example, in the 70's someone added a humbucker in the neck and a pickup selector. You can tell they really cared by how they installed it, attempting to bevel the pickguard and all. That's not to say they did a great job, but the care was there and they tried to do it right. Drilling a hole in a chassis and top panel to accomplish what the footswitch accomplishes is pretty goofy regardless of the value of the amp at the time... imo of course! Hindsight 2020

@mohamedtlass3842 10 ай бұрын

People were often on drugs back then and made all sorts of dumb decisions… like the goofs that painted my 61 Bandmaster and 1935 National-Dobro amps black