Search found 758 matches
- Thu Jun 23, 2016 11:50 pm
- Forum: Technical Discussion
- Topic: Phase Inverter Distortion
- Replies: 5
- Views: 1445
Re: Phase Inverter Distortion
It is increasing the "load." Similar to increasing the load in a truck. Poorer acceleration and deceleration.
- Wed May 11, 2016 12:25 am
- Forum: Technical Discussion
- Topic: Grid Resistor Value Determinations
- Replies: 11
- Views: 3924
Re: I'll look at the information you posted
............Another question- If there is no substantial current flowing in the bias circuit, how do different value bias feed resistors affect the bias on the output tubes? ..............silverfox. The flow of current in the bias circuit does not flow thru the grid / bias feed resistors. The bias ...
- Wed May 04, 2016 11:06 pm
- Forum: Technical Discussion
- Topic: Preamp bias-vary tremolo schematic/layout
- Replies: 2
- Views: 736
Re: Preamp bias-vary tremolo schematic/layout
http://el34world.com/charts/Schematics/files/airline-wards/Airline-Wardss_gvc-9058a.pdf http://el34world.com/charts/Schematics/files/harmony/harmony_h410.pdf http://el34world.com/charts/Schematics/files/kalamazoo/kalamazoo_m2s.pdf http://el34world.com/charts/Schematics/files/gibson/Gibson_skylarkga5...
- Sun Apr 24, 2016 2:23 am
- Forum: Technical Discussion
- Topic: Danelectro 6sj7 Vibrato
- Replies: 6
- Views: 1390
Re: Danelectro 6sj7 Vibrato
Should be about 8ma thru that resistor at idle. Screens would draw more at louder outputs since class AB.
2200=v/.008
.008x2200=v
v=17.6
w=va
w=17.6x.008
w=0.14
No way that resistor needs to be that big. I like a ~3watter early is a PS that small.
2200=v/.008
.008x2200=v
v=17.6
w=va
w=17.6x.008
w=0.14
No way that resistor needs to be that big. I like a ~3watter early is a PS that small.
- Thu Apr 14, 2016 12:30 am
- Forum: Fender Discussion
- Topic: Princeton Reverb vs Deluxe Reverb clean output volume
- Replies: 10
- Views: 2797
Re: Princeton Reverb vs Deluxe Reverb clean output volume
Has it been documented that a stock PR clips in the PI or preamp before the 6v6s? I know my DR clips in the 6v6s 1st so cleaning up or increasing voltages in its preamp or PI isn't going to provide more clean output from the speakers. I know the PR has a cathodine PI which does not provide signal bo...
- Wed Mar 23, 2016 8:41 pm
- Forum: Trainwreck Discussion
- Topic: CTS pots New vs Vintage
- Replies: 10
- Views: 2308
Re: CTS pots New vs Vintage
30% seems way to close to liner to work in a volume application to me. The graphs I've seen all show ~10% for non linear and non-reverse types.
- Fri Feb 19, 2016 12:50 am
- Forum: Technical Discussion
- Topic: Touch-Sensitivity: Myth or Reality?
- Replies: 24
- Views: 3274
Re: Touch-Sensitivity: Myth or Reality?
Check out Dave Edmunds' "Baby Let's Play House." Especially the last 5 seconds. No better example in a song that I know of.
https://www.youtube.com/watch?v=5NHjEW01DsM
https://www.youtube.com/watch?v=5NHjEW01DsM
- Wed Feb 10, 2016 12:24 am
- Forum: Technical Discussion
- Topic: Measuring Screen Grid Dissipation
- Replies: 35
- Views: 4523
Re: Measuring Screen Grid Dissipation
Using DC measurements under signal may or may not be numerically accurate depending on the meter. But the increasing reading is in the right direction since this is most likely class AB. A scope is needed to see for sure.
- Sat Feb 06, 2016 9:12 pm
- Forum: Technical Discussion
- Topic: SE EL34 Plexi-verb
- Replies: 137
- Views: 12125
Re: SE EL34 Plexi-verb
The input to the Belton is grounded in the scheme. Not sure if that was pointed out. It should probably go only to the wiper of the pot.
- Tue Jan 12, 2016 12:29 am
- Forum: Fender Discussion
- Topic: 79 Deluxe Reverb volume problem
- Replies: 9
- Views: 2447
Re: 79 Deluxe Reverb volume problem
Make sure the path to ground is good. I think this means its physical mount to the chassis in this case.
- Sat Dec 19, 2015 3:16 am
- Forum: Technical Discussion
- Topic: Adjustable cathiodbiae
- Replies: 5
- Views: 1008
Re: Adjustable cathiodbiae
I use 2 470ohm resistors + 2 100ohm pots on a pair of 6v6s to do this. Pots are 5wt wire wound. Each has its own bypass cap.
- Sat Dec 12, 2015 6:28 pm
- Forum: Technical Discussion
- Topic: How do you tell a customer...?
- Replies: 23
- Views: 2593
Re: How do you tell a customer...?
The scheme in the link shows 10" (not 10 ohms.) Both in the scheme section and the parts list section. My The Tube Amp Book is 4.1 and I don't see it there.
- Sat Dec 05, 2015 1:39 pm
- Forum: Fender Discussion
- Topic: Deluxe Reverb Build
- Replies: 15
- Views: 3140
Re: Deluxe Reverb Build
At 18ma per OP tube that's probably only about 40-45ma total draw. More draw brings down the voltage somewhat. I run my '71 DR op tubes around 25ma on the plates and the plates are at 440v. (11 watts) If you increase the idle the voltage will come down somewhat. Of course you want to stay within acc...
- Sat Dec 05, 2015 1:22 pm
- Forum: Technical Discussion
- Topic: DC on grid of preamp tube
- Replies: 4
- Views: 1216
Re: DC on grid of preamp tube
DC stabilization on a grid is not optional. Either DC coupling or a grid leak of some sort to ground or bias. I accidentally left one off once and I heard bzzzzzzzzzzzzt thru the speaker. Added it in an there was no damage.
- Wed Nov 25, 2015 1:20 am
- Forum: Technical Discussion
- Topic: Debugging some home-made amp problems
- Replies: 9
- Views: 1255
Re: Debugging some home-made amp problems
Near the top of the pic is a red wire that is black-taped to the chassis. Above the tape it appears to have burnt insulation. No?