MiKro Posted September 25, 2020 Author Report Share Posted September 25, 2020 I bought a new de-soldering tool the other day. Expensive Hakko one. It is now going back, as it started to sound like a Jet engine revving up after about 20 mins of use. Man I hate it when things fail. MK 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted September 26, 2020 Author Report Share Posted September 26, 2020 I got the wires in place for the push pull pots. All color coded so I can use lugged P/P pots, what a PITA. Need to clean up the joints some but I am much happier now. mk And for Carl, You can see the silicone on the caps now. I also replaced the 350 ohm 10 watt resistor as the other had cracks. 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted September 27, 2020 Author Report Share Posted September 27, 2020 Dang it I found 2 more electrolytic caps on the EQ board hiding under the cables. LOL Have to fix those as well.. They are going to be a bitch to get to as the slider bodies are in the way. MK OLD New 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted September 27, 2020 Author Report Share Posted September 27, 2020 Since I cannot get PCB type push/pull 250K linear pots anywhere anytime soon I went with lugged p/p pots. what a bitch to add. So I had to add wires and make it all somewhat flexible so they will fit in the chassis. Here is one done. My soldering looks like hell. hard to do while floating in air. LOL Damn I need to get to my real workbench. I will clean them up once mounted so they are in place and not moving. LOL MK 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted September 27, 2020 Author Report Share Posted September 27, 2020 So testing the fit, one more p/p-pot to do then I can go back together with this thing. Got to clean it up first It's not pretty as the originals but will function fine and get the job done. LOL MK Quote Link to comment Share on other sites More sharing options...
RonMay Posted September 27, 2020 Report Share Posted September 27, 2020 I didn't know Greece was so green. And your thinking "Greece, what's this have to do with Greece?" Well, it's Greek to me. Looks complicated. Total respect for anyone who can understand that so this. Ron 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted September 27, 2020 Author Report Share Posted September 27, 2020 Well it is now back in the chassis for the final test fit. I can now remove, it clean it, then go back together,. LOL mk 2 Quote Link to comment Share on other sites More sharing options...
MiKro Posted September 30, 2020 Author Report Share Posted September 30, 2020 So the secondary wires are in as well as the heater wires, A few ground wires and the standby switch. I moved the the Standby switch and small ground wires to the back side of board. Relocated the heater wires to allow me to get some distance in height above the secondaries to help on hum. Hopefully that will help? A few more wires to do, Check solder joints again and re-flow any that need it. Then to finish cleaning and recheck everything again. Then it's time to do the slow process of startup and test. MK Here you can see where it was update to the 93 upgrades 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 1, 2020 Author Report Share Posted October 1, 2020 Oh so close. I had an LED that was a problem. I had to rewire the p/p pot to fix that. Other than that, all is looking good so far. Tomorrow will be try it with tubes and make adjustments. Hopefully soon it will be right. Fingers crossed. MK 1 Quote Link to comment Share on other sites More sharing options...
Bizman62 Posted October 1, 2020 Report Share Posted October 1, 2020 After a puff of smoke it's time to double check the connections... 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 1, 2020 Author Report Share Posted October 1, 2020 5 hours ago, Bizman62 said: After a puff of smoke it's time to double check the connections... @Bizman62 HAHA!! No smoke so far. All is good. Going through the slow steps of startup as if I built this from scratch. MK . 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 1, 2020 Author Report Share Posted October 1, 2020 Just fired it up with tubes. sounds very good. Iused the old preamp tubes and the new power tubes. I then put the new preamp tubes in and 2 were DOA So I have to send them back. MK 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 2, 2020 Author Report Share Posted October 2, 2020 Other than waiting on the new preamp tubes this is done. Looks great for circa ( 1989 ) and it sounds awesome again mk 2 Quote Link to comment Share on other sites More sharing options...
curtisa Posted October 2, 2020 Report Share Posted October 2, 2020 Good enough for late-80s Steve Vai Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 2, 2020 Author Report Share Posted October 2, 2020 2 minutes ago, curtisa said: Good enough for late-80s Steve Vai Damn Skippy it was. Some Frank Zappa as well. 1 Quote Link to comment Share on other sites More sharing options...
curtisa Posted October 2, 2020 Report Share Posted October 2, 2020 I didn't realise until recently that the song 'Blue Powder' on Vai's Passion and Warfare album was initially recorded as a demonstration piece for the Carvin X100B. Guitar Player magazine used to have those removable vinyl records you could tear out of the magazine and play back on a tuntable, and it appeared on one of those in something like 1985 or '86. When Vai released P&W in 1990, he just remixed the original recording and stuck it on the album. Pretty cool to think that such a wild song was actually much older than the album it appeared on 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 2, 2020 Author Report Share Posted October 2, 2020 1 hour ago, curtisa said: I didn't realise until recently that the song 'Blue Powder' on Vai's Passion and Warfare album was initially recorded as a demonstration piece for the Carvin X100B. Guitar Player magazine used to have those removable vinyl records you could tear out of the magazine and play back on a tuntable, and it appeared on one of those in something like 1985 or '86. When Vai released P&W in 1990, he just remixed the original recording and stuck it on the album. Pretty cool to think that such a wild song was actually much older than the album it appeared on I always laugh at people that swear by Marshall and think that the early Carvins were a joke. Only for a few years 1988/ 1989 ( also the only years of the carpet exterior) did the x100b have only EL34 as power tubes. The ones before and after you could use EL34s or 6L6s and there was a bias switch for them. This gave it the ability to more than compete with any Marshall of the time. As it could get just as gritty and growl with the best of them using the 6L6 output/power tubes. change to the El34s and they could get cleans that no Marshall ever could. Adding the 5 band EQ made the 3 Treb. Mid, Bass controls even more flexible. than a Marshall Don't get me wrong I have nothing against a Marshall, but for the money the Carvin was overall the best deal out there for the same sound in my opinion. MK 1 Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 3, 2020 Report Share Posted October 3, 2020 Shame they aren't more common. 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 3, 2020 Author Report Share Posted October 3, 2020 8 hours ago, Prostheta said: Shame they aren't more common. I know , they really are good amps. Harder to find now but still can get them for cheap compared to an old Marshall or Fender 1 Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 3, 2020 Report Share Posted October 3, 2020 Well, they both have the weight of their respective names and a lot of momentum behind their products. No idea how Marshall managed to sneak the JCM900 past us you know? 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 3, 2020 Author Report Share Posted October 3, 2020 So now I am taking an old Peavey footswitch with 3 switches and going to make it work as an FS36XLR footswitch for this X100B. I don't have a footswitch for this and to get a replica is about $85.to $100 Wish me luck. LOL. UPdate : That is done. MK 1 Quote Link to comment Share on other sites More sharing options...
MiKro Posted October 9, 2020 Author Report Share Posted October 9, 2020 Well guys the new preamp tubes came in today. I must say, this thing is frigging killer. I forgot how good one of these amps can sound. No more pops, scratches when knobs are turned. only a slight hum when at 100 watts and full volume ( expected ) OMG this thing is like brand new again. I am very pleased with my efforts and I know the Doctor will be as well. Recap of work: Replaced all of the electrolytic capacitors, replaced bad power resistors and a few others, added an adjustable bias pot, replaced all of the potentiometers, rerouted wires to minimize hum, replaced all tubes, and eliminated ground loops. Rewired an old Peavy 3way footswitch with XLR connector to work as a Carvin replacement foot switch. WOW is all I can say. MK 3 Quote Link to comment Share on other sites More sharing options...
Djstatix Posted June 27, 2022 Report Share Posted June 27, 2022 I’m interested in the bias board you made. Any help with parts used and pics would be nice. Quote Link to comment Share on other sites More sharing options...
MiKro Posted June 27, 2022 Author Report Share Posted June 27, 2022 49 minutes ago, Djstatix said: I’m interested in the bias board you made. Any help with parts used and pics would be nice. They are posted in the first page of this thread. Very easy to make. Post number 4 in the thread. BTW circuit was checked and verified by Rob Robinette mk Quote Link to comment Share on other sites More sharing options...
Djstatix Posted June 27, 2022 Report Share Posted June 27, 2022 4 minutes ago, MiKro said: They are posted in the first page of this thread. Very easy to make. Post number 4 in the thread. mk I can see the board and resistor. That potentiometer, where did you get it? Looks like r126 is the insertion point. Quote Link to comment Share on other sites More sharing options...
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