Search found 1599 matches
- Thu May 16, 2024 4:59 am
- Forum: Fender Discussion
- Topic: 1976 Fender Vibrolux refresh help
- Replies: 4
- Views: 63
Re: 1976 Fender Vibrolux refresh help
for the added fuse, check what is this and why is there
- Thu May 16, 2024 4:56 am
- Forum: Fender Discussion
- Topic: 1976 Fender Vibrolux refresh help
- Replies: 4
- Views: 63
Re: 1976 Fender Vibrolux refresh help
all electrolytic capacitors needs replacement.. another critical point are film capacitors after the PI to the output tubes, they need to be replaced too.. all those moves are preventive and cheap..all elcos are too old and can fail anytime in the future. on other positions film caps should be measu...
- Mon May 13, 2024 5:06 pm
- Forum: Technical Discussion
- Topic: Can I Parallel 2 Mosfets in VVR?
- Replies: 19
- Views: 452
Re: Can I Parallel 2 Mosfets in VVR?
connecting mosfets in parallel can easily lead to a silicone pop-corn
- Fri May 10, 2024 7:25 pm
- Forum: Garage Talk
- Topic: Congrats Amplified Nation!
- Replies: 10
- Views: 955
Re: Congrats Amplified Nation!
Im just reading feedbacks on FB Tube Guitar Amplifiers group..not looking good..reliability problems?
https://www.facebook.com/groups/724815140961013/
posts down
https://www.facebook.com/groups/724815140961013/
posts down
- Fri May 10, 2024 11:13 am
- Forum: Dumble Discussion
- Topic: Couple of #183 derivatives
- Replies: 70
- Views: 11114
Re: Couple of #183 derivatives
Well you've got at least one dud there. Have you considered using thermistors for a soft start instead of a standby switch? not really , because you need to hold high voltage at least 20-30 seconds and if not.. all of the Ub line caps will be on max voltage .. You need something like 500k. So or Au...
- Fri May 10, 2024 11:02 am
- Forum: Dumble Discussion
- Topic: Couple of #183 derivatives
- Replies: 70
- Views: 11114
Re: Couple of #183 derivatives
Yes, and the voltage drops are there too in the same time.. on variac if i lower the input voltage, then in one moment is ok situation, but on nominal looks like is going to the white smoke.
Chasing the ghost
- Fri May 10, 2024 6:38 am
- Forum: Dumble Discussion
- Topic: Couple of #183 derivatives
- Replies: 70
- Views: 11114
- Fri May 10, 2024 6:29 am
- Forum: Dumble Discussion
- Topic: Couple of #183 derivatives
- Replies: 70
- Views: 11114
Re: Couple of #183 derivatives
Here is something what happened after in the amp.. failure on 450V elcos in the preamp section (they were new Kemet - Long life - ex Rifa) ? Very strange, i didnt measure wall voltage before.. maybe little bit over 230? Looks like caps took surge voltage during cold start (power and standby switch p...
- Fri May 10, 2024 4:53 am
- Forum: Dumble Discussion
- Topic: Couple of #183 derivatives
- Replies: 70
- Views: 11114
Re: Couple of #183 derivatives
For the past weekend we had some festival dedicated to vinyl and tubes, where was amp played.. i took nude and rude version without box.. Very nice experience.. maybe little bit too fatty/creamy sound with 1x12" Alnico Cream.. room and people damped the heights so better in the start to have more mi...
- Fri May 10, 2024 4:45 am
- Forum: Garage Talk
- Topic: Psycho-fonics - Blind testing
- Replies: 2
- Views: 82
Re: Psycho-fonics - Blind testing
I wonder if anyone can actually call out a tube by hearing it. not possible.. also there is wide range of manufacturing types and shapes..but you can hear the differences.. and NOS are at least 30% better than modern tubes.. Altough i have good luck with 12AX7 JJ, often they are good enough-till-gr...
- Wed May 08, 2024 5:31 pm
- Forum: Technical Discussion
- Topic: ID this tube?
- Replies: 7
- Views: 221
Re: ID this tube?
ECC81 most probably , need to put tube on the tester to see the currents
- Wed May 08, 2024 5:18 pm
- Forum: Garage Talk
- Topic: The rack is Back?! Maybe not for everyone, but at least for me !
- Replies: 9
- Views: 489
Re: The rack is Back?! Maybe not for everyone, but at least for me !
about tube preamps.. they are here all the time, real built and durable.. not those pcb+processors garbage types.. they have 0 value it is actually a shooting in his own legs to go this route, but they will realise after some years what a fail this is..IMO
- Wed May 08, 2024 5:14 pm
- Forum: Garage Talk
- Topic: The rack is Back?! Maybe not for everyone, but at least for me !
- Replies: 9
- Views: 489
Re: The rack is Back?! Maybe not for everyone, but at least for me !
Hey Bepone, Thanks for the clarification. My plan is not to drive the amp with a multi effect, but rather to have a lot of flexibility between preamps and power amps coupling. I have a musicman PT and OT that I would like to couple them with any preamp to get the feel of those 700V without building...
- Fri May 03, 2024 8:29 am
- Forum: Technical Discussion
- Topic: JTM45 Build, looks alive but no sound,
- Replies: 7
- Views: 265
Re: JTM45 Build, looks alive but no sound,
if there is a scope, then is easy..
1. remove NFB wire
2. put 100mV signal on the input
3. trace to the output tubes pin 5
blind shot..i suspect there is no gnd wire on some tubes, missing
1. remove NFB wire
2. put 100mV signal on the input
3. trace to the output tubes pin 5
blind shot..i suspect there is no gnd wire on some tubes, missing
- Fri May 03, 2024 8:23 am
- Forum: Dumble Discussion
- Topic: Transformer transplant
- Replies: 25
- Views: 756
Re: Transformer transplant
So my questions are: That original wiring of the speaker jack, grounded with the bias pot, is that correct, or is it a design flaw from the manufacturer?? yes If so, this makes me question the rest of the grounding scheme in this amp, so I'll then have to take a deeper look at the rest. Could you p...