YOUR CF Tube Amp Build Progress

mine has a switch thanks to you roy!! so far no problems!! like I told harry, think maybe not having one is causing alot of the problems people are having with their amps!!

Well, I fixed George's amp tonight / this morning, he had his B+ circuit backwards.

Instead of feeding the B+ off the transformers, through the diodes, to the large cap, to the internal fuse, to the output transformer taps & the large blue resistor, through the smaller large cap and to the ground; he fed the B+ through the diode, through the large blue resistor, to the output transformer taps, thought the fuse, through the large cap and BACK into the B+ circuit.

He blew up the large blue resistor, both fuses in the amp (internal one first because the amp came on when Roy had it), and I am surprised he didn't blow a cap.... The amp now works and will be on its way ASAP.




Don's amp however, is a different story....

Everything "looks" fine, but the left channel does not work..... I get a rather loud buzz like you get when you touch a headphone jack on a headphone-RCA wire, and I cannot read a schematic.... I appreciate Roy's help this morning, he tried, but even his layman (spellcheck) terms were WAY over my head....

We ruled out tubes, the rca jacks & wires, anything touching that shouldn't be, no grounded jacks, and right channel works fine....

A huge thanks to Alex and Roy-- you guys just made my day.

Don's amp however, is a different story....

Everything "looks" fine, but the left channel does not work..... I get a rather loud buzz like you get when you touch a headphone jack on a headphone-RCA wire, and I cannot read a schematic.... I appreciate Roy's help this morning, he tried, but even his layman (spellcheck) terms were WAY over my head....

We ruled out tubes, the rca jacks & wires, anything touching that shouldn't be, no grounded jacks, and right channel works fine....

Alex, don't know anything about zeneers, but I think you mentioned amp worked before the zeneer install. Could that have something to do with it. May we have a bad zeneer, whatever the heck they are? Should we uninstall the zeneers and see if it works again? Or the extra RCA jacks, could one of those be shorting since installed at same time as zeneers?

If all else fails, just put my signed transformer covers by Bob on Wayne's amp and mail off to me!

May we have a bad zeneer, whatever the heck they are?

...Vote this in the Hall of Fame!!!! ...

If all else fails, just put my signed transformer covers by Bob on Wayne's amp and mail off to me!

...

Yep-- Wayne has so much stuff,, he'll never know--it'll take years for him to roll tubes--Merry Christmas Wayne,, you know I love you..

So roy, when you increased the fuse rating on georges amp did that correct the problem?

Roy. George assembled 2 amps were they both defunked ? The first one he finished he took home with him which is the one that started blowing fuses. The second one went home with Alex to figure out what was wrong with it. Was this the way it was george? So alex and Roy figured out what was wrong with one of the amps (wiring issue) What about the other?

Don's amp however, is a different story....

Everything "looks" fine, but the left channel does not work..... I get a rather loud buzz like you get when you touch a headphone jack on a headphone-RCA wire, and I cannot read a schematic.... I appreciate Roy's help this morning, he tried, but even his layman (spellcheck) terms were WAY over my head....

We ruled out tubes, the rca jacks & wires, anything touching that shouldn't be, no grounded jacks, and right channel works fine....

Alex, don't know anything about zeneers, but I think you mentioned amp worked before the zeneer install. Could that have something to do with it. May we have a bad zeneer, whatever the heck they are? Should we uninstall the zeneers and see if it works again? Or the extra RCA jacks, could one of those be shorting since installed at same time as zeneers?

If all else fails, just put my signed transformer covers by Bob on Wayne's amp and mail off to me!

Unfortunately, I ruled that out last night... The Zeners are fine, they are also hooked into the channel that works... As far as the RCA's, I checked to make sure they were not grounded, and they were not! If you want to check your amp at the house, take a volt meter and measure the conductivity from the MAIN ground off of the power transformer to the INSIDE of the RCA jacks, if it makes a contact on the INSIDE pin of the RCA Jack, it's grounded and must be replaced, if not, it is fine!

Roy. George assembled 2 amps were they both defunked ? The first one he finished he took home with him which is the one that started blowing fuses. The second one went home with Alex to figure out what was wrong with it. Was this the way it was george? So alex and Roy figured out what was wrong with one of the amps (wiring issue) What about the other?

This is half correct, One amp went home with George and then was taken to PolkFest where it was handed off to Roy because it stopped working. It then made it's way to me yesterday. The other amp is with Aunders up in PA with the Toms. He thought he could figure out what is wrong with it and took it home. Unfortunately, I do not know if he got it to work correctly, so......

By now you have figured out that building amps, or any electronics for that matter, from scratch is not a simple plug and play event. Even using pictures versus a schematic will not show you technique or the reasoning behind why. You have also found that a picture perfect copy doesn't always work or in an amps case, be quiet. It was a huge gift for Bob to offer such a kit, but impossible to teach a lifetimes worth of knowledge in a week. I'm not saying the amps can't be made to work and quietly but will require time, paitence and a little help.

No real help in this post, just letting you know it's not easy. No one here is an idiot, stupid or hopeless. You are not born with knowledge. Electronics is a skill learned. Both in theory and practical application.

^^^ well said^^^

Harry-- the second amp left Bob scratching his head,,and Anders too,,so it went back to Pittsburgh--I'll call them and post an update

What Is a Zener Diode Regulator?

Zener diodes are primarily designed to regulate the output voltage of a power supply. As a voltage regulator, a stable maximum voltage is allowed to pass through the diode. This maximum voltage is determined by the voltage rating of the zener diode. Regulation of a specific voltage output ensures electronic equipment does not receive electrical power surges. These surges often destroy electronic components in computers, televisions and other electronic equipment.



http://www.reuk.co.uk/Zener-Diode-Voltage-Regulator.htm

anybody want to make a bet on how many of the six amps i have to finish building might have issues?

So roy, when you increased the fuse rating on George's amp did that correct the problem?

No, he also had a B+ issue. Unplugging and replugged PS plug can cause a surge current draw that why I recommend a 4 amp fuse for those who plug and unplug.

Monoblocks in Tha House!!!!!...Arrived in good shape...TUBE TIME!!!!!