Yes it will be OK trying the SSLV1.1 with those transformers
150 or 120 Ohm dummy will be more representative, like 110 or 140mA at 17V, depending on your DCG3 bias
My experience with an early preamp prototype of shared shunt reg is that the SSLV will need two wire mode with DCG3 to be clean of MHZ band anomalies but not sure for every different finalized DCG3 installation. If without a scope to check the rails are clean, better go two wire mode
Reading your post prior to this you indicated that you connected SE reference to DCG3 G. You should connect it to In- on the DCG3 not G. A balanced amp does not care whether you feed a balanced signal or SE across In+ and In-.
nash
It seem it depents on the sourse and perhaps on the load too. One safe conclusion is that R7s should stay grouned. From there on, best configuration has to be found for each system indepentently. As long as it work it's OK!
Thanks Salas I will sort out the correct resistors. The intention is to go dual mono with the supplies.
No Joy Day
Hi,
I forgot to insulate the Mosfets before power up and have likely caused some damage to the power supply (possibly more). The inboard LEDs blinked and their respective fuses blew.
I insulated the mosfets and replaced fuses and now read +24.3V and -6.6V ( on minus and plus rails respectively). The other side is about the same.
Where do I look?
TIA
Keith
Hi,
I forgot to insulate the Mosfets before power up and have likely caused some damage to the power supply (possibly more). The inboard LEDs blinked and their respective fuses blew.
I insulated the mosfets and replaced fuses and now read +24.3V and -6.6V ( on minus and plus rails respectively). The other side is about the same.
Where do I look?
TIA
Keith
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Are those voltages without the amp board connected? I hope so.
24v means the led's and regulator diodes aren't doing their job. Actually, this is kind of a good thing...at least it's somewhere to start. You have a straight shot from the transformer. Replace leds and then semis is probably where I would start.
-6v means something is broken, maybe caps got reverse voltage but you are losing voltage somewhere. I'd measure voltage at the first cap after the rectifier to see that you are getting -24. Once you get to the leds if you have -24v you know the problem is after that.
If you replace the leds and the semis on the psu board you should be ok. Resistors look ok?
The amp board is another story...but if you can fix the psu you can start debugging it.
24v means the led's and regulator diodes aren't doing their job. Actually, this is kind of a good thing...at least it's somewhere to start. You have a straight shot from the transformer. Replace leds and then semis is probably where I would start.
-6v means something is broken, maybe caps got reverse voltage but you are losing voltage somewhere. I'd measure voltage at the first cap after the rectifier to see that you are getting -24. Once you get to the leds if you have -24v you know the problem is after that.
If you replace the leds and the semis on the psu board you should be ok. Resistors look ok?
The amp board is another story...but if you can fix the psu you can start debugging it.
The fuses could have saved the large transistors in the PSUs but the BC550 & BC560 are likely gone.
Just finish my DCG-3 build. I use MUSES72320 electronic pot kit from Japan which has 20k ohm impedence.
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Everything working fine so far. Many thanks for Salas and Tea.
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Everything working fine so far. Many thanks for Salas and Tea.
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Congratulations. First one here with a Muses chip-pot I believe. Let us know more about your system and how it blended in after you run it enough to grasp the qualities.
Hi Salas,
I see Seanwu uses two outputs connected in parallel. Is it the right way to have two independent outputs?
I assume that usege of output 1 or 2 is ok. But if to use both at the same time (like 1 for power amp and 2nd for power Subwoofer), then we need to add resistor.
We discussed that subject on Hypnotize/Mesmerize B1 buffer forum with Andrew.
I see Seanwu uses two outputs connected in parallel. Is it the right way to have two independent outputs?
I assume that usege of output 1 or 2 is ok. But if to use both at the same time (like 1 for power amp and 2nd for power Subwoofer), then we need to add resistor.
We discussed that subject on Hypnotize/Mesmerize B1 buffer forum with Andrew.
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Absolutely properly for two outputs it is done with a jumper on the PCB 50R output resistor's place and one 50R inline with each RCA output. Then again because its a strong driving circuit that does not care much about total cable capacitance it has to be compared to say its detectable or not vs just Y after the common 50R.
Using the Muses attenuator it already has input capacitors to that chip and an expensive Muses DC servo op-amp for its output on its own little PCB so there are even more things to consider vs a typical DCG3 configuration.
Using the Muses attenuator it already has input capacitors to that chip and an expensive Muses DC servo op-amp for its output on its own little PCB so there are even more things to consider vs a typical DCG3 configuration.
Also been planning implementation of a Muses volume control in the DCG3.
Havent ordered the kit yet.
But - another linestage is coming into the house in a week or so. And this has the muses already installed.
Will compare the DCG3 with this just for the fun of it. Its a high end pre costing approx 3300USD direct from manufacture.. After using the DCG3 for a while now I really think it will be hard to beat...
Havent ordered the kit yet.
But - another linestage is coming into the house in a week or so. And this has the muses already installed.
Will compare the DCG3 with this just for the fun of it. Its a high end pre costing approx 3300USD direct from manufacture.. After using the DCG3 for a while now I really think it will be hard to beat...
Hello Salas
I would like to add an output with fixed value to use as recording output.
I do not know if I can just feed the input directly to the recorder or if I should pass the signal through the preamp.
Please let me know your opinion
I would like to add an output with fixed value to use as recording output.
I do not know if I can just feed the input directly to the recorder or if I should pass the signal through the preamp.
Please let me know your opinion
When you want a REC OUT of fixed level and not passing through the DCG3 circuit, you can tap signal off the input selector switch and buffer it via something simple on a small perfboard like a DCB1 style CCSed JFET source follower or some op-amp voltage follower. The +/-17V rail can also provide power for such solutions. Buffered is better. Both it isolates the recorder to the DCG3 and drives the recorder's interconnects better.
Ricardo,
I had similar thoughts also, but if you pass the signal through the preamp it won' t be with fixed output, as the signal will have to go through the volume control.
The only way to have fixed volume tape out is to take the signal before the pot.
If your source can drive the tape input and the cables you will have a problem, otherwise a buffer only for tape out is necessary.
I had similar thoughts also, but if you pass the signal through the preamp it won' t be with fixed output, as the signal will have to go through the volume control.
The only way to have fixed volume tape out is to take the signal before the pot.
If your source can drive the tape input and the cables you will have a problem, otherwise a buffer only for tape out is necessary.
Ok. So buffer i will use. Dcb1 style but running at +-17v.
This buffer will be connected before the pot so it will be parallel to it. As it is jfet input the high input impedance will not affect the rest. And the signal input can be chosen by the existant relay board. Good
Btw, after changing the shunts with new ones prepared for 17v and also changing the compensation cap in the dcg3 feedback, it sounds spectacularly well with my new mosfet power amps.
This buffer will be connected before the pot so it will be parallel to it. As it is jfet input the high input impedance will not affect the rest. And the signal input can be chosen by the existant relay board. Good
Btw, after changing the shunts with new ones prepared for 17v and also changing the compensation cap in the dcg3 feedback, it sounds spectacularly well with my new mosfet power amps.