Search found 109 matches
- Mon Aug 11, 2014 2:20 am
- Forum: Technical Discussion
- Topic: Ampeg VT-22 loud crackling/popping
- Replies: 15
- Views: 3472
Re: Ampeg VT-22 loud crackling/popping
I'm about 99% sure this is not an OT short. I've never seen an amp with an OT short that didn't blow the HT fuse immediately upon taking it off standby. Today, I was testing coupling caps and resistors, and at one point, the amp crackled loudly, stopped, and then I had full power. Of course, the amp...
- Sun Aug 10, 2014 6:20 am
- Forum: Technical Discussion
- Topic: Ampeg VT-22 loud crackling/popping
- Replies: 15
- Views: 3472
Re: Ampeg VT-22 loud crackling/popping
thanks for the advice. i have checked nearly all resistors in the amp, now. all b+ dropping resistors check out okay, as do all of the cathode resistors. some have shifted value slightly, but nothing extreme. all voltages check out OK per the schematic, all tubes have been replaced.. the noise is co...
- Fri Aug 08, 2014 7:27 pm
- Forum: Technical Discussion
- Topic: Ampeg VT-22 loud crackling/popping
- Replies: 15
- Views: 3472
Re: Ampeg VT-22 loud crackling/popping
Hm, I guess I should also note that when the popping and static does subside, (It seems to have "chilled out" a bit) the output is extremely low. Can someone shed some light as to what this might be symptomatic of? Still crossing my fingers for that PI tube. If the OT is shot...
- Fri Aug 08, 2014 6:01 am
- Forum: Technical Discussion
- Topic: Ampeg VT-22 loud crackling/popping
- Replies: 15
- Views: 3472
Re: Ampeg VT-22 loud crackling/popping
It seems to happen no matter how much tube swapping I do. Tapping on components with my wooden stick does not seem to trigger or exacerbate the noises. All solder joints look good, and all components are affixed firmly to the PCB. Banging on the amp doesn't do it either. So it leads me to believe th...
- Wed Aug 06, 2014 11:34 pm
- Forum: Technical Discussion
- Topic: Ampeg VT-22 loud crackling/popping
- Replies: 15
- Views: 3472
Ampeg VT-22 loud crackling/popping
I have been using this amp as my primary gigging amp for awhile now without too many issues. Replaced to 6AN8 PI tube and some preamp tubes, replaced some toasty looking resistors, and all has been well. Today, I had the amp turned on for a couple of hours. Playing through it at very low volumes per...
- Mon Jun 09, 2014 10:10 pm
- Forum: Technical Discussion
- Topic: passive low cut/hi pass filter in guitar
- Replies: 4
- Views: 716
passive low cut/hi pass filter in guitar
not amp related, but you guys know your stuff... wondering if this is possible. pickups are too dark, but have a very high output. is there anyway to cut say, 180hz and below with a few caps?
- Sun Jun 01, 2014 7:25 pm
- Forum: Technical Discussion
- Topic: SE + PP amp
- Replies: 9
- Views: 1339
Re: SE + PP amp
Yeah, that is a good idea, and what I was aiming for. I guess in the end you would just be building a preamp, two power amps and an attenuator. If I do decide to attempt this build, an SS poweramp might not be a bad idea...
- Sun Jun 01, 2014 6:44 pm
- Forum: Technical Discussion
- Topic: SE + PP amp
- Replies: 9
- Views: 1339
SE + PP amp
I really do love the sound of a SE 5-6w amp, but of course, they aren't loud enough for gigging unless you are playing a venue with a legit PA, which isn't always the case on tour. Got me thinking, has anyone tried to build, say, a SE using just a 12ax7 and el84/6v6, then used a step down xfmr to br...
- Sat May 31, 2014 5:47 am
- Forum: Technical Discussion
- Topic: reverb schematics
- Replies: 11
- Views: 1455
reverb schematics
anyone have any leads on some good spring reverb circuit schematics? This would be my first attempt at incorporating reverb into one of my builds. anything I should be looking out for or paying special attention to?
- Tue May 27, 2014 9:58 pm
- Forum: Technical Discussion
- Topic: Why are my tubes running so hot?
- Replies: 26
- Views: 3102
Re: Why are my tubes running so hot?
Alright, my new JJ 6L6GCs came into today. Popped them in, and hoped for the best. They draw more current, 31ma a piece, but my b+ plate and screen voltage dropped. At -31vdc the plates are at 380. I am getting just as much if not more distortion. So at this point, I think I'm going to grab a pair o...
- Sun May 25, 2014 5:22 am
- Forum: Technical Discussion
- Topic: Crazy vintage ceramic cap price on ebay...
- Replies: 13
- Views: 1215
Re: Crazy vintage ceramic cap price on ebay...
Also 7 dollars to ship something the size and weight of a paper clip. This is so stupid!!
- Sun May 25, 2014 5:21 am
- Forum: Technical Discussion
- Topic: Crazy vintage ceramic cap price on ebay...
- Replies: 13
- Views: 1215
Re: Crazy vintage ceramic cap price on ebay...
.1 what? Thanks for the stellar description. Haha.
- Sun May 25, 2014 12:04 am
- Forum: Technical Discussion
- Topic: Why are my tubes running so hot?
- Replies: 26
- Views: 3102
Re: Why are my tubes running so hot?
The bias pot was a little wonky. I completely rebuilt the bias circuit and used exact values, and a brand new 2 watt locking pot. I get about 28 volts of AC current on the output at peak, and I'm going to guess around 1.2 to 1.5 amps. which would be around 38-40 watts of power, i think. again, curre...
- Sat May 24, 2014 4:01 pm
- Forum: Technical Discussion
- Topic: Why are my tubes running so hot?
- Replies: 26
- Views: 3102
Re: Why are my tubes running so hot?
Tilly, yes it was r14 and r15. I've checked my work many times over, I should have known that I couldn't have made such a stupid mistake as wiring the power tubes incorrectly. Wishful thinking that it would be something so easy. :lol: Here are some pics, quite a few since the space is small and its ...
- Sat May 24, 2014 12:53 am
- Forum: Technical Discussion
- Topic: Why are my tubes running so hot?
- Replies: 26
- Views: 3102
Re: Why are my tubes running so hot?
Oh no... Could I have my bias voltage and grid voltages on the wrong screens?! I will check when I get home and post pics.