Thats the variation with the BJT voltage supply. Mine is the vanilla copy.
Regards
while i am in bamboo cage ,... feed me with bananas .dont forget to serve them with silver tinned PCBs with glass epoxy laminate...At the moment of 240V shock.... .i will shout Awuooooo! ...And then I could refuse to let him out of the bamboo cage after that and auction him to the highest bidder. I'm sure many ladies will bid their life savings for him ...hyeah: :licklips:
Cheers
That may be a dummy ckt , how come it be mains powered directly ... Here we see 3 trafo guarding us from going to hell at any moment The Grounded Grid preamplifierI don't have access to any literature. I look at provided information only.
This is what is provided in the link mentioned:
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He has a reputation for being difficult ...he has communicated only in one liners and 4 word sentences all along. My CC expired and I told him my friend would pay online on my behalf. He refused and stopped responding to my emails after that. Edit: .. and 2 months have gone by with no communication ...
I have no intention of renewing my CC either.
Regards
Power on delay to avoid POP sound![]()
That may be a dummy ckt , how come it be mains powered directly ... Here we see 3 trafo guarding us from going to hell at any moment The Grounded Grid preamplifier
I got original design in Audio Reality
simulation plots as in analog metric forums :![]()
Voltage gain of this GG preamp is 12dB.
@kaushik - that 10K bleed resistor is not required, neither is the Darlington pair, or the use of the B/E junction of the transistor as a diode dropper. For delay I use a single BD139, and a largish cap and resistor combo to give me a nice long delay. 100K and 470uF yields around 6 seconds. A BD139 is able to switch three relays - this is needless complexity for a simple circuit.
Edit: Tube power amps use an output transformer, and are pretty immune to DC at the input. SS amps are not. There is obviously some issue with the circuit that cause a DC imbalance so late in the day. A delay of more than 10 seconds is unreasonable - even my 40-year old Garrard radiogram would take about 8 seconds to reach operating conditions. Anyway, for 12 seconds delay a timer is a better bet than a R/C combination - though it could still be done.
Any contacts in the signal path potentially affect the sound quality, specially mechanical ones in a relay. So yes, it could affect SQ.
However, it affects it considerably less than a blown speaker, so I would use some kind of standby switch. Normally, I would simply switch on the power amp a minute or two after the preamp - which I kind of do anyway since even my source has a bit of a pop at switch-on...
In this circuit, only the relay is in the signal path. The components used to switch the relay are not interfering with the signal.
@kaushik - that 10K bleed resistor is not required, neither is the Darlington pair, or the use of the B/E junction of the transistor as a diode dropper. For delay I use a single BD139, and a largish cap and resistor combo to give me a nice long delay. 100K and 470uF yields around 6 seconds. A BD139 is able to switch three relays - this is needless complexity for a simple circuit.
Edit: Tube power amps use an output transformer, and are pretty immune to DC at the input. SS amps are not. There is obviously some issue with the circuit that cause a DC imbalance so late in the day. A delay of more than 10 seconds is unreasonable - even my 40-year old Garrard radiogram would take about 8 seconds to reach operating conditions. Anyway, for 12 seconds delay a timer is a better bet than a R/C combination - though it could still be done.
The bleeder resistor provide a discharge path for the capacitor, ya may be omitted if the other circuitry there to provide a path.. for isolated delay ckts i think it ensures that the delay time is reset on power cut.
circuit works the BE juction breakdown (like a zener) , there are many alternatives for delay,a smd ckt 555 timer in 1 sqcm is better and compact solution and can be fitted on a OMRON type relay top,if i use it the the large leaded cap (cheap) will standing on a plastic cap.
Gobble,
we can use the OMRON relay that is used in the remote attenuator, even most amps use a power on delay relay..nothing to worry.. it is like someone holding the rca connction and joining it thatz all.
gobble,ur rig when done is gonna be quite something to listen to when done :licklips:.hope i can audition it some day.cheers
If your preamp in solid state and comes with a pcb, there is little need to use twisted pairs. Most twisted pairs are used in Valve amps. Not solid state.
If your preamp is laid out correctly. You can use ribbon cable. It is much better are it rejects stray signals pretty good.
Always use co-ax for the items that you stated in your thread. Cat5E cable is not a good cable to use. It is for video and DSL.
Use stranded wire. It is more forgiving.
Solid wire is for those who work on old phone lines and radio. Not so good for audio work.
Ribbon cable comes with many colors that you can use for signal, power, ground circuit or chassis. It offers a lot of uses.
Take away from teflon wire. It is to hard to prepare and clean. Plus it cost more and does not improve your signal or product
Take Care
Ivey