Laboga Alligator

Рет қаралды 2,225

Күн бұрын

Join this channel to show your support & get access to perks:
/ @bradsguitargarage
Webpage: www.bradsguitargarage.com.au
Facebook: bradsguitargarage
Instagram: / bradsguitargarage
Equipment:
Soldering:
Pace MBT station w/SX100 & PS-90 handpieces
Hakko 474 w/815 handpiece
Hakko 936 w/907 handpiece
Hakko FX-888D w/FX-8801 handpiece
Quick 861DW hot air station
BOFA fume extraction unit
Loctite Multicore solder (C511 / 362)
Test Equipment:
Fluke 11, 175, 177 & 179 handheld DMM's
Tektronix 2236 analog oscilloscope
Rigol DS-1054z digital oscilloscope
BK Precision 4017A sweep / function generator
BWD 160a function generator
HP 6236B triple output DC power supply
Kyoritsu 3132A insulation / continuity tester
Video equipment:
Overhead cam: Panasonic HC-V785 w/Audio Technica AT9946CM mic
Handheld cam: Panasonic DC-G85 w/Olympus M.Zuiko Pro 12-40mm f/2.8
On location cam: Panasonic DC-GH5s w/Panasonic-Leica 9mm f/1.7 & 12-60mm f/2.8
Capture card(s): Magewell HDMI USB, ATEN UC3020-AT, ATEN UC3021
Headset Mic: Audio Technica BP892xcW-TH
Lapel Mic: Rode Go
Editing: Adobe Premiere Elements
Hand Tools:
Wiha, Felo, Stanley screwdrivers
CK & Engineer cutters / pliers
RS Pro wire strippers
Sidchrome & Gear Wrench spanners, sockets & shifters
Veritas planes & chisels
Materials / Consumables:
JJ's / TAD electron valves
Elixir / Ernie Ball / D'Addario / Rotosound strings
Electrolube & DeoxIT cleaners, lubricants & chemicals.

Пікірлер: 45

@thatampguy 2 ай бұрын

You had me at alligator.

@goodun2974 2 ай бұрын

In Oz-land, it should be Crocodile, not alligator!

@martinreid1740 2 ай бұрын

Thanks for this Brad, not the sort of amp I would like. I'm old school now,seventy and just used old Fenders which never let me down. As far as I'm concerned the more complicated a circuit is the more can go wrong. I gigged for forty years and never had a problem with the old Fender amps, my brother bought an orange when they first came out and it's still working now. Best wishes from Scotland.

@BradsGuitarGarage 2 ай бұрын

Good way of thinking, mate! It can be difficult for people requiring a wide range of tones on tap. For such people, either a multi-fx or modeller is the way to go, and just accept that will be broken in 5-6 years too, likely irreparable, and they'll just need to buy a new one. There are real amps that can do it very well, and they can be incredibly well built, but they have price-tags to match, as they should! However, the vast majority on the market are poorly designed and not built to last. People think all of us techs are just negative and cynical in this regard, but we see all the broken stuff, and it's just the simple, hard truth.

@greblus 2 ай бұрын

Adam Laboga was an amazing guy, sadly no longer with us. When I was a teenager, cheap SS Laboga amps were the only way to go. Looked and sounded cool 😊

@tedmich 2 ай бұрын

Nice work Brad, amps sound good! No bad pizza!

@jamesunderhill1603 2 ай бұрын

Sounds alright. Reverb tank is stupid though

@robertbull6895 2 ай бұрын

Hey Brad. Great investigation and analysis. I have note similar “active” circuitry (op amps) in the feedback loop of an Ashton VP50 combo several years ago. I will have another look and follow your lead in using a cro to analyse the signal path. Displaying waveforms and spectrum analysis can tell so much. Thanks.

@BradsGuitarGarage 2 ай бұрын

My GOD they are those horrid Chinese schematics that are a nightmare to read! What you are looking at there is what is called a "gyrator" and it's essentially a solid state equivalent of an inductor-based graphic EQ band control. IC4, R100, C66 & R101 form the gyrator. This is a filter which is boosting or cutting a certain frequency band in the feedback loop (I don't have time to analyze what freq. band or Q). Bear in mind that by cutting a band in the feedback loop, you've actually boosted it in the resultant output signal. And vice-versa.

@goodun2974 2 ай бұрын

@@BradsGuitarGarage, so, it's basically a tunable "presence" circuit, allowing you to increase or decrease the negative feedback at certain frequencies. Some older Japanese hifi equipment puts the bass and treble controls in a feedback loop as well.

@BradsGuitarGarage 2 ай бұрын

@goodun2974 yes, that is likely the case.

@zulufrog 2 ай бұрын

You must have been cranking it pretty good on the distortion channel, I was watching the logo vibrating while you played. Nice sounding amp, but, damn big price tag for what I saw in there.

@BradsGuitarGarage 2 ай бұрын

Yes, it's a curious position for the logo too, I thought.

@terrydemol5354 2 ай бұрын

Interesting vid Brad, looks like a PITA repair. Laboga is Polish, manufacturing costs lowish over there with decent expertise and technology. I've repaired a few, IMV they represent just OK value. That stage is a CFP (complimentary feedback pair) with gain. T4 (master) controls T5 (slave) and FB through R62 / R66 set up gain. Here with the additional FB from OP and master inside the loop just make things complex with questionable benefits.... and it's after the FX loop. Different isn't always better. :) Did you give the 100k trimpot a jiggle?

@BradsGuitarGarage 2 ай бұрын

It was just a bit of everything all adding up to one symptom, which can be frustrating to explain to the customer. I left the trim-pot as-is. That stage seemed to be functioning as designed.

@AlanW 2 ай бұрын

$3k for a transistor clipping amp, crazy.

@baabaabaa-yp2jh 2 ай бұрын

Why have a master vol? Who makes em, never heard of em Brad? Edit: luv the reverb!!

@baabaabaa-yp2jh 2 ай бұрын

Cleans sound great !

@JamieTyson 2 ай бұрын

Sounds better than i expected it to, but that could just be the tone in your hands!!

@matthewf1979 2 ай бұрын

Toneskin!

@BradsGuitarGarage 2 ай бұрын

I need to remember to practice the night before and warm up before a demo, considering playing at all is now a luxury with the given workload.

@yaanno 2 ай бұрын

this PPIMV looks strange. the type-2 supposedly works better with fixed bias amps. as you mentioned a large grid stopper could take care that ugly distortion

@johnbriggs3916 Ай бұрын

If the question was never asked, how can you be sure that the answer was wrong? 😉

@guywithoutthought 2 ай бұрын

Now I'm deffo no expert, but could it be, that they were trying to do a Badcat style 'K-Master' type thing there?

@BradsGuitarGarage 2 ай бұрын

Not sure, but I'll look into that. Thanks mate.

@ianmccutcheon6759 2 ай бұрын

$4500? Wow. With the knobs, it reminds me of a crate on the outside. Inside is like the Peavey Classic Series. Sounds decent but that's a lot of money.

@BradsGuitarGarage 2 ай бұрын

After doing a little research, the market price appears to be mid-$3000's at the moment.

@jutukka 2 ай бұрын

How does it sound if you plug your guitar into that foot sw jack under that input jack? 😁

@BradsGuitarGarage 2 ай бұрын

I accidentally did that at one point. How did you know!?!?

@jutukka 2 ай бұрын

@@BradsGuitarGarage Because I am not stupid, just a bit retarded. And I can read your mind. 🥸 And I have read the story of that famous American aerospace engineer Edward A. Murphy Jr. 🤓

@goodun2974 2 ай бұрын

@@BradsGuitarGarage, most of us would have done the same at some point; I know I would have!

@goodun2974 2 ай бұрын

Sticking foam onto a circuit board is never a good idea. Most foams become corrosive eventually; sometimes they become conductive!

@ddqd123 2 ай бұрын

No idea why boutique builder would cheap out on a PCB. Those "savings" (maybe $20/amp?) probably all get eaten up in assembly costs and warranty returns.

@doggwoggle 2 ай бұрын

what? assembly costs are the reason PCBs are used. Because they make assembly cheaper. A lot cheaper.

@ddqd123 2 ай бұрын

@@doggwoggle I mean use a cheaper thinner single-sided PCB vs a double-sided thru plated vias with extra copper (2oz vs the standard 1oz)

@goodun2974 2 ай бұрын

@@ddqd123 , thru-plated vias and double-sided boards are over-rated, at least for guitar amplifiers. I'm now retired from electronics repair, but if I had to work on something for which service info was sketchy or non-existent, I'd much rather have a single-sided board where it's fairly easy to trace the foils and circuit paths by eye. Also, modern manufacturers seem to have a tendency to make the plated holes in the board (the vias) barely large enough for the diameter of the component lead, and therefore removing all of the old solder so you can pull a part out becomes difficult even with a vacuum-operated desoldering station, typically requiring several cycles of applying fresh solder and sucking it out. An appropriately sized plated via is probably a good idea for a hot running resistor, diode, regulator, or tube socket since it holds the part more securely and there's less chance of the solder joint breaking down from heat and vibration, but for most other parts it becomes a royal pain in the neck. Radial filter caps don't need plated through holes, and removing "snap-in" caps from a double-sided PCB can be an exercise in frustration. Double-sided PCBs should be left to heavily digitized circuits where that type of board is appropriate and necessary.

@michaelmarchei8539 2 ай бұрын

$4500 for that steaming pile. Fk that

@BradsGuitarGarage 2 ай бұрын

After doing a bit of cursory research, the market price appears to be in the mid-3000's. I'd still like to see some finer touches for that price, but it's miles ahead of a lot of amps that charge a lot more. At any rate, thanks for watching, mate!

@Splattle101 2 ай бұрын

WTF were they trying for with this design?

@BradsGuitarGarage 2 ай бұрын

Seems well-meaning, but kinda defeats itself, eh?

@FXClinic 2 ай бұрын

Wait....what? Is that a "fuzzface-esque" circuit before the PI turning on following the feedback signal path???? what?

@BradsGuitarGarage 2 ай бұрын

Fuzzface-esque? Interesting, I did not initially recognize that. I'll need to look into that!

@FXClinic 2 ай бұрын

@@BradsGuitarGarage Just reminded me of that, looking at those transistors in a glance. I could be wrong, and probably am.

@nigelgunn322 2 ай бұрын

Soldering on those valveholders is a bit blobby. Probably made by a kid in China.

@BradsGuitarGarage 2 ай бұрын

Yes, I debated myself w/regard to cleaning and re-doing the PCB but did not want the bill to blow out even more and it was presented as stable in that area. A constant internal struggle not to re-do everything, though!