I remember servicing one of these from that era. Honestly the best sounding amp I ever played. Came in needing the basics (cleanup, filter caps, checkup etc), and since it didn’t come with a back panel, the owner wanted me to put a replacement. As part of wanted the replacement back panel, he wanted a top boost mod. After cleaning it up, new caps I was playing it, and the bright channel (sans top boost), by itself or jumpers with the normal channel just blew me away to the point I tried talking him about not “wasting” the money adding a top boost. We compromised by me using a DPDT switch to toggle in and out the top boost circuit, as well as a push pull on the volume pot to give him the option of bypassing the bright cap on the volume that is present as part of top boost..so he could have modes of stock bright, stock bright + bright cap, tb stock, tb w/o bright cap. In any case this was by far the best amp I ever played. And even though the cabinet was a bit rough, the important things were fine- stock transformers, celestion silver bells, and tubes.
I LOVE this idea. Best of both worlds and then some. The amp in the video belongs to me, so I’ll definitely be discussing your suggestions with Lyle. Thanks for sharing!
@@peterdawson1834 let me be clear on this so you are fully aware: on the one I serviced there was no back panel for the cabinet, so as I fabricated one for the customer, I fabricated it with the hole cut out of it. I wouldn’t have ever been willing to cut a big hole like that (2”x4”) in a good vintage cabinet. Secondly, the top boost mod also required me to fabricate a metal plate and brackets to hold the extra tube and circuitry for it, so it’s definitely more than a simple component swap
Hi, thanks for another great video. I was given a 65 grey panel top boost that had these round white resistors, every single one was more than 100% out of tolerance. I replaced them all with carbon film since that is what is available in Australia, but I am very keen to see how you put the fuse on the HT. I've put back up diodes on the GZ34 but better safety for the old Woden transformers cant hurt. Thank you again, I am learning heaps from watching your videos. Much appreciated Mic
I really do appreciate the attention to detail you put into the work you carry out. Hopefully it will inspire the next generation of designers, builders and technicians out there to better things.
You rarely hear it because most people these days go for a “top boost” model that replaces the treble channel. IMHO, the stock treble channel on the old AC30 like this are the best sound you can get from one.
Thanx for telling what desoldering braid you use. That Techspray #4 prowick is incredible! It absorbs solder like a sponge! It’s pricey but I don’t care. I’ve tried a few braids with no luck whatsoever. Even using a flux pen didn’t help. I was starting to wonder why they even made these things.
Great video, thank you. I have a '65 AC100 that I received with a blown power transformer, so when I replace it, I'll also look to install an HT fuse and review the heater wiring. Is Mercury the go-to for this era Vox amp replacements, especially the AC100?
Was zapped pretty good only once... 10yrs old. My friends basement stored a cool phonograph amp that we plugged in. One of the tubes was broken, but glowing orange. Wondered how hot it was, so touched it with my finger...lightly. My friend told me that my body did two somersaults across the basement where a wall stopped my flight... If ya need a pick-me-up, would suggest a strong cup o' coffee. NOT a zap...😉😎👍 Have you given the UAFX Ruby Vox AC30/TB a listen yet? This layout of this Vox you're servicing is really interesting. Like the looks of it.
But now for the important question. What was for lunch to tackle the really meticulous part. The next time you tackle something tricky, may I suggest a Reuben with pumpernickel instead of rye. 👍🏻
Can you explain the Dave Peterson mod for the Vox amps & what exactly it does? Apparently Thom & Jonny in Radiohead both have it but I can't find any info on what it actually is.
So, how close to the socket pins should the heater wires be twisted? I've seen some twisted right up to the pin, some an inch or more away from the pin and some heater wires not twisted at all. Also, what solder braid do you use? The stuff I've tried so far "doesn't suck".
Over the years I have mostly used Chem-wick desoldering braid, aka "solder wick", from Chemtronics; but I've also used Weller, Hakko, Pomona and GC brands with good results. Buying off-brands through eBay or Alibaba is likely to be very much hit or miss. Note that the copper braid needs to be shiny and bright, and because it's impregnated with powdered rosin flux it should have almost a whitish frosty look to it. If the copper is reddish brown it's probably old and oxidized and might not work well. Also note that the tip of your soldering iron will need to be scrupulously clean, and you will need to tin the tip of the iron with a little bit of fresh solder just before using it in conjunction with the solder wick. An oxidized, dirty soldering iron tip will not conduct heat to the braid very well. Perhaps most important of all, you will invariably need to add fresh solder to the connection *before* you put the desoldering braid and soldering iron to it, especially if the connection was originally made with lead free solder. Dabbing the solder wick with a little bit of extra rosin flux in paste form can also be helpful but usually isn't necessary if it's good quality, fresh solder wick. Be advised that there are a lot of out of unscrupulous sellers marketing soldering flux to electronics hobbiists which is actually acidic and corrosive and made more for plumbing or sheet metal work then for electronics. I've seen people, including those who are experienced at electronics and should know better, buying fluxes online only to find out when it arrives that it says right on the bottle or can that it is not recommended for electronics work.
I remember servicing one of these from that era. Honestly the best sounding amp I ever played. Came in needing the basics (cleanup, filter caps, checkup etc), and since it didn’t come with a back panel, the owner wanted me to put a replacement. As part of wanted the replacement back panel, he wanted a top boost mod. After cleaning it up, new caps I was playing it, and the bright channel (sans top boost), by itself or jumpers with the normal channel just blew me away to the point I tried talking him about not “wasting” the money adding a top boost. We compromised by me using a DPDT switch to toggle in and out the top boost circuit, as well as a push pull on the volume pot to give him the option of bypassing the bright cap on the volume that is present as part of top boost..so he could have modes of stock bright, stock bright + bright cap, tb stock, tb w/o bright cap. In any case this was by far the best amp I ever played. And even though the cabinet was a bit rough, the important things were fine- stock transformers, celestion silver bells, and tubes.
I LOVE this idea. Best of both worlds and then some. The amp in the video belongs to me, so I’ll definitely be discussing your suggestions with Lyle. Thanks for sharing!
@@peterdawson1834 let me be clear on this so you are fully aware: on the one I serviced there was no back panel for the cabinet, so as I fabricated one for the customer, I fabricated it with the hole cut out of it. I wouldn’t have ever been willing to cut a big hole like that (2”x4”) in a good vintage cabinet.
Secondly, the top boost mod also required me to fabricate a metal plate and brackets to hold the extra tube and circuitry for it, so it’s definitely more than a simple component swap
This feels like watching Bob Ross.
Hi, thanks for another great video. I was given a 65 grey panel top boost that had these round white resistors, every single one was more than 100% out of tolerance. I replaced them all with carbon film since that is what is available in Australia, but I am very keen to see how you put the fuse on the HT. I've put back up diodes on the GZ34 but better safety for the old Woden transformers cant hurt. Thank you again, I am learning heaps from watching your videos. Much appreciated Mic
Oldie but a goodie. Looking forward to the next video. Thanks Sir.
I really do appreciate the attention to detail you put into the work you carry out. Hopefully it will inspire the next generation of designers, builders and technicians out there to better things.
Love the care and attention to detail. Glad it’s getting the Lyle treatment - second to none!
Always be careful when “heating up that joint”…..what an art that you do.
When it’s your amp, it’s peace of mind that you try.
Well done! My early 1960s Vox AC 30 looks exactly the same as this one internally!
Another old but great historic amp lives on for the next generation to admire and covet its lovely sound. The Amp-Gods are happy.
Even the sound through the lav mic is really cool. I like that Treble channel sound. It's got a character to it you don't hear often! 🙂
You rarely hear it because most people these days go for a “top boost” model that replaces the treble channel. IMHO, the stock treble channel on the old AC30 like this are the best sound you can get from one.
Thanx for telling what desoldering braid you use. That Techspray #4 prowick is incredible! It absorbs solder like a sponge! It’s pricey but I don’t care. I’ve tried a few braids with no luck whatsoever. Even using a flux pen didn’t help. I was starting to wonder why they even made these things.
Great video, thank you. I have a '65 AC100 that I received with a blown power transformer, so when I replace it, I'll also look to install an HT fuse and review the heater wiring. Is Mercury the go-to for this era Vox amp replacements, especially the AC100?
Was zapped pretty good only once...
10yrs old. My friends basement stored a cool phonograph amp that we plugged in. One of the tubes was broken, but glowing orange. Wondered how hot it was, so touched it with my finger...lightly.
My friend told me that my body did two somersaults across the basement where a wall stopped my flight...
If ya need a pick-me-up, would suggest a strong cup o' coffee.
NOT a zap...😉😎👍
Have you given the UAFX Ruby Vox AC30/TB a listen yet?
This layout of this Vox you're servicing is really interesting.
Like the looks of it.
But now for the important question. What was for lunch to tackle the really meticulous part. The next time you tackle something tricky, may I suggest a Reuben with pumpernickel instead of rye. 👍🏻
Can you explain the Dave Peterson mod for the Vox amps & what exactly it does? Apparently Thom & Jonny in Radiohead both have it but I can't find any info on what it actually is.
So, how close to the socket pins should the heater wires be twisted? I've seen some twisted right up to the pin, some an inch or more away from the pin and some heater wires not twisted at all. Also, what solder braid do you use? The stuff I've tried so far "doesn't suck".
Over the years I have mostly used Chem-wick desoldering braid, aka "solder wick", from Chemtronics; but I've also used Weller, Hakko, Pomona and GC brands with good results. Buying off-brands through eBay or Alibaba is likely to be very much hit or miss. Note that the copper braid needs to be shiny and bright, and because it's impregnated with powdered rosin flux it should have almost a whitish frosty look to it. If the copper is reddish brown it's probably old and oxidized and might not work well. Also note that the tip of your soldering iron will need to be scrupulously clean, and you will need to tin the tip of the iron with a little bit of fresh solder just before using it in conjunction with the solder wick. An oxidized, dirty soldering iron tip will not conduct heat to the braid very well. Perhaps most important of all, you will invariably need to add fresh solder to the connection *before* you put the desoldering braid and soldering iron to it, especially if the connection was originally made with lead free solder. Dabbing the solder wick with a little bit of extra rosin flux in paste form can also be helpful but usually isn't necessary if it's good quality, fresh solder wick.
Be advised that there are a lot of out of unscrupulous sellers marketing soldering flux to electronics hobbiists which is actually acidic and corrosive and made more for plumbing or sheet metal work then for electronics. I've seen people, including those who are experienced at electronics and should know better, buying fluxes online only to find out when it arrives that it says right on the bottle or can that it is not recommended for electronics work.
Joe Morgan Inc.?