I’ve had RadioShack replace warranted tubes. A pair of 7199 from an EICO amp. The clerk had never been briefed on it. I showed her the warranty statement. She made a few calls and we filled out some paperwork. They took the duds. Six months later a pair of NOS RCA appeared in the mailbox. This was about 2005. They sold mostly cell phones and batteries by then. It was a fun day.
I realy like your videos, you take great pride in your work amd do everything properly. There's none of this "I'll whack this capacitor in here, it's not the right one but it should work" No, you take great pains to get it right, wish there were more techs out there like you!
I should have known better than to click on this video right before bed.... This is not the place to find a quick video before bed.. I'll watch this another day :P
44:56 - Curious about the 'X6' remark. Why woudn't the chart just show an R.P. of 183 without the 'X6' remark? Also, in your calculation, how did you get '17'?
Did you Ever Demo this? I couldn't seem to find how it sounded after service. The seem like a hidden gem amongst the Fender Giant that so dominates the amp landscape. I have a 65' Reverberocket but Im looking for more power/headroom. Although they were built for clean jazz playing, its gets damn raucous quickly.
Personally I would change the bias supply circuit to not have the bias pot in series. Main problem that can occur is if the bias pot fails open then you lose bias voltage. The safer way to install the bias pot is in parallel to ground. That way if the pot fails open the negative bias voltage supply will remain intact. A failed bias pot in that manner will leave the tubes biased as cold as they can be set.
Thanks for watching! The way the circuit is designed, if the pot goes open, there will be no shunt across the bias supply to bring it down. The bias voltage will go up to max negative voltage and shut the tube down. I will be showing the schematic in a later video. I just didn't have it finished at the time I posted this. Thanks again!
I thought I saw the Ampeg schematic showing the bias pot in series. Thanks for sharing this video and your schematic revisions with us, looking forward to the next video.
Is there a good way to remove that glue from the pcb? I have a Sansui with the same issue and I want to remove it proper without me, or the glue destroying the amp. Thanks for a great channel!
1968? TIME is what broke down those capacitors. WVDC is different than surge voltage. CE FP caps really are TRASH. Hayseed Hamfest makes can caps to order. There is a lengthy lead time right now, but they WORK.
Yeah all that goopy stuff poured all over the amp is such a shame. I think Ampeg was trying to do things in different ways than Fender or other prominent amp makers.
