Those amps look very well made. You made it sound like a really nice Fender combo just by hooking up that capacitor again, the previous tone was like my pals old AC30 top boost which never had a valve changed for 40 years but had that big warm tone(at full blast volume). Great video, it's good to see inside these boxes at-least to see how much effort goes into the layout and design. Seems like everything is based on a Vox, Fender, Marshall,Hiwatt, Orange foundation but some of em have improved on them a lot. There are lot of really great Guitar amps available and at the same time a lot of total crudd too. It took me a while to remember what the older Geezers used to bore with;" Keep it simple stupid" , less to go wrong, if I would have taken heed I would have saved a lot of time and dough wasted on gadgets just to get a sound that I already had but only needed a new Valve or 2...maybe a speaker too. Thanks for sharing your skills, don't underestimate how much better the customer feels when he gets his amp back to the band/studio and finds out how much better the music is after all the work you did.
Hi Lyle. Great work as usual👍🏽 A tip for 15 watt Matchlesses: For some unknown reason Matchless has decided to have an impedance-mismatch in their output transformers. So they always have a plate to plate-load of 4k Ohms, regardless if they’re running four or only two EL84s in the output stage. If the amp has an 8 Ohm speaker, the tubes will live happier and sound better, if you compensate for this mismatch by connecting it to the 4 Ohm tap on the transformer. Personally, I think - judging from the clip - that the bright cap was a bit too “effective” 😉 I would probably go with a lower value cap or perhaps a series resistor between the cap and the pot. But as always this is down to personal taste. Keep up the spirit and the good work👍🏽😉
The component layout is probably quite well thought because there is very little wire spaghetti all over the place to collect hum and noise. Mainly just component leads from point to point. Nice, I like that. Of course it is not a hyper gain multistage cascaded multichannel amp, so amount of wiring is quite minimal anyways.
Oh yeah! Highlights were only ever seen by me at the pediatrician's office and the dentist's office waiting rooms. Good ol' Goofus & Gallant and how about "WHAT'S WRONG WITH THIS PICTURE" from Highlights? We play that one a few times a day on my bench.
I built a Spitfire clone for a guy a few yeas ago. Really cool sound out of the thing. It had a really great glassy, Voxy vibe. I had no idea Matchless used one, two and three watt carbon comp resistors in their amps. Those look like genuine Allen-Bradley’s too. The typical values in those resistors are unobtanium these days.
Have you, or will you post any Fryette, or Fryette era VHT repairs or walk throughs? That would be fascinating! Fryette is very outspoken about his methods and tight with schematics.
Is the way that those input resistors are directly mounted from the input jack to a tagstrip alright? Will that not cause an accidental loss of signal if the input jack comes loose and spins, possibly pulling the resistors out of its solder joint?
The mic position may of been different after you re-attached the bright cap vs after the mods cause it sounded more harmonic compared to the later sound test. If not maybe it’s the sound of running the tubes dangerously hot creating it.
First pat of the video was with my shop cab aimed more at my/the mic’s position. Bright cap was Matchless cab/speaker off axis. You’ll get to hear the real sound soon.
Just curious. Why doesn’t anyone use a pot for adjustable cathode bias? Like put a minimum 80 or 100ohm resistor and then like a 200 ohm wire wound pot?
Think it’s something to do with the reliability of the pot being affected. A better method is to wire a pot as a variable resistor in series with the cathode bypass, this varies the amount of bypass, effectively gives the same gain boosting effect, but there’s less dc load on the pot.
I've never understood why some people immediately cut the bright cap in their amps, especially without first trying a different speaker. To my ears cutting the bright cap is like throwing a blanket over your amp. It takes away all the character of the amp, and a lot of times its ability to cut through a mix or band. Just turn down the treble pot, people!
Spitfire is a great name for a fighter plane. For an amp, not-so-much. The visual image that name evokes isn't something I'd want from any electronics. Just sayin' ...
