Search found 15705 matches
- Fri Feb 16, 2024 1:59 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Yep, you maybe need to compensate for any gain change. Its the S/N ratio that matters in this case. Also, you tend to get that sort of noise/f curve depending on the type of noise source (thermal, shot, partition etc ). Generally paralleling devices will reduce noise proportionally to square root of...
- Thu Feb 15, 2024 11:11 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Yep the noise will reduce for every doubling of the FETs. I think there is a error though. The 40r source resistor is shorted out
- Thu Feb 15, 2024 9:28 am
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
The gate resistor will be needed for each one. in case you don't know, its job is to protect the fet if the input is sent too +ve. The gate/source junction will become a forward biased diode (as shown in the symbol) and its to prevent excess current in that case. This is one of these bits of informa...
- Wed Feb 14, 2024 9:49 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
You can play with the source resistor in the case of the jfet to alter the gain, and also try paralleling up 2 or more.
- Wed Feb 14, 2024 5:11 pm
- Forum: Everyones Projects
- Topic: 6550 SE Amplifier
- Replies: 110
- Views: 9407
Re: 6550 SE Amplifier
I normally use 100R on ecc88, I would have thought 10k would be more than enough.
- Tue Feb 13, 2024 7:57 pm
- Forum: Assorted Stuff
- Topic: Zero emission road vehicles.
- Replies: 912
- Views: 397332
- Tue Feb 13, 2024 7:54 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
The small signal section is for AC analysis of fr and phase. It may be you need to set that depending on the analysis you are showing. The left hand side is for voltage/current against time.
- Tue Feb 13, 2024 11:22 am
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Are you using AC on the input? if so, whats the 1.4V
- Mon Feb 12, 2024 10:08 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Q2 is upside down.
- Sun Feb 11, 2024 10:18 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
You should be able to ground the stepup metalwork, while leaving the windings floating. It may be ok to ground the primary if needed, but try and leave the secondary grounded via the phono stage.
- Sun Feb 11, 2024 6:35 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Yes, and also, because the input is now floating (assuming the cartridge is wired as is normal so the output is not connected to earth), any voltage generated in the 0v line down to the ground point at the output RCA's is not seen by the input valve as its common mode WRT the input.
- Sat Feb 10, 2024 12:55 am
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Maybe.
- Fri Feb 09, 2024 11:34 pm
- Forum: Valves
- Topic: Valve amplifier service
- Replies: 176
- Views: 84256
Re: Valve amplifier service
Is the single cap C14 to allow ripple currents in the bridge to have an easy path to mains supply earth? Maybe, sounds like could be correct. Not ripple though, its 10nf, so will be to pass switching noise from the diodes I would have thought. HF signals will see the wire to the other end of the 0v...
- Fri Feb 09, 2024 11:30 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Looks like fun, but going from *4 to *10 is not that trivial.
- Fri Feb 09, 2024 10:06 pm
- Forum: Everyones Projects
- Topic: C3g Aikido Phono
- Replies: 319
- Views: 81268
Re: C3g Aikido Phono
Just look at the phono circuit and think about the voltages you have and then think about the currents required to generate those voltages.