Yes I did all the metalwork too. This is a hobby after all but it took me about a month to make the chassis😛
I like the sound of that masking tape though - got any pics😉
I like the sound of that masking tape though - got any pics😉
Nice job Martin
whats the DAC hiding inside Homebrew or Kit i was thinking of implementing a DAC in my Clones finished enclosure
Thanks
Koogar
whats the DAC hiding inside Homebrew or Kit i was thinking of implementing a DAC in my Clones finished enclosure
Thanks
Koogar
The DAC is also Peter's design and kit. Its the boards and components from his NOS DAC premium kit, but adapted to include both Toslink and coax inputs. The power comes from adding some custom windings on the transformer (so I can remove the PS section of the DAC kit's board) and the other two parts are cut in half as they wouldn't fit in the chassis otherwise.
Again, all design credit goes to Peter, I just followed instructions and looked at his pics to get an idea of what was happening. He has pics of an integrated including a DAC in the same chassis lurking on here, just do a search.
I will say that his NOS DAC kit is something special. I have nothing to compare it with but the sound I get now is way ahead of anything I have experienced before.
Again, all design credit goes to Peter, I just followed instructions and looked at his pics to get an idea of what was happening. He has pics of an integrated including a DAC in the same chassis lurking on here, just do a search.
I will say that his NOS DAC kit is something special. I have nothing to compare it with but the sound I get now is way ahead of anything I have experienced before.
In some photos of the gc3875 that Peter built I saw a rather large resistor installed between the star ground and the chasis. Can anyone tell me what the purpose of this would be?
Hi, I'm building the 3875 Premium kit, and have a few questions.
1. I am using a 40v-0v-40v Torroidal transformer. It is an 800 VA unit that I got off ebay that was from a PVA7 amplifier (PVA 7 - Welcome to the New Official Anthem® Audio Video Website.), and i realize it has more power than is required, but will it work? Is that too much voltage? Can I reduce it if I need to, and how?
2. Since this Tansformer is a Center tap, only three wires on the output do I follow:
http://www.diyaudio.com/forums/chip...oid-wiring-peter-daniels-kit.html#post1196283 ? so if I read this properly i will connect my two wires with voltage to AC1 and AC2 one on the inside hole and one on the outside hole. the common wire will then go to the CHG hole in both Amp boards.
1. I am using a 40v-0v-40v Torroidal transformer. It is an 800 VA unit that I got off ebay that was from a PVA7 amplifier (PVA 7 - Welcome to the New Official Anthem® Audio Video Website.), and i realize it has more power than is required, but will it work? Is that too much voltage? Can I reduce it if I need to, and how?
2. Since this Tansformer is a Center tap, only three wires on the output do I follow:
http://www.diyaudio.com/forums/chip...oid-wiring-peter-daniels-kit.html#post1196283 ? so if I read this properly i will connect my two wires with voltage to AC1 and AC2 one on the inside hole and one on the outside hole. the common wire will then go to the CHG hole in both Amp boards.
The resistor there is to block ground noise from the AC line from entering the amplifier. (The alternative is a straight wire from star ground to chassis.) Your system may or may not benefit from the resistor, depending on how noisy your AC's ground is, but since the resistor is not directly in the signal path, there doesn't seem to be any harm in putting it in.
Thanks for the info. My AC ground seems to be quiet. But for future reference what values would the resisitor have?
The voltage is far too high.
25Vac to 27Vac is for 8ohm speakers.
18Vac to 22Vac is for 4ohm speakers.
40Vac is for >150W into 8r0 and ~300W into 4r0.
I thought the Chip spec's for the AMP can do 80volts
If the chip's spec's can do 80 VAC why can I not use a 40v-0v-40v?
I must be missing somthing. When I measure the voltage I get +40 Volts on both sides using the center as the common.
If the chip's spec's can do 80 VAC why can I not use a 40v-0v-40v?
I must be missing somthing. When I measure the voltage I get +40 Volts on both sides using the center as the common.
you cannot possibly measure +40Vdc on an AC scale when attached to the AC voltage coming from the secondary winding.
Yes, You are missing something: it is 80V DC, not AC, When converting AC to DC it multiplies approx 1.5x
fluke
do you like you fluke i have one just like it's never missed a beat i used it for years when i was an auto mech tech now i'm retired and just play with audio
best regards bill
do you like you fluke i have one just like it's never missed a beat i used it for years when i was an auto mech tech now i'm retired and just play with audio
best regards bill
the headphone uses much lower level signals.
The chipamp will probably sound noisy on headphones.
The chipamp will probably sound noisy on headphones.
Actually, GC works very well as headphone amp: http://www.diyaudio.com/forums/headphones/62828-lm3875-headphone-amp-another-try.html
That's been suggested here: http://www.diyaudio.com/forums/audi...ne-kit-building-instructions.html#post1508778
Hey guys
Thought i would show you my finished Kit and chassis to spur some of the first timers like me on
its the Classic kit built as an integated amp 300va 2x25v
The chassis was a scratch built by me from aluminium with a temp Corian front panel before i get a 10mm aluminium plate CNC machined.
The 48mm Volume knob was souced on Ebay from seller 8audio based in china but delivery was quick .
I would just like to thank Peter for all his help on the forum
I wrote a quick and dirty guide below for bending aluminium if anyones interested in making their own chassis
http://bit.ly/d7ayVE
Have fun
Rupert
Thought i would show you my finished Kit and chassis to spur some of the first timers like me on
its the Classic kit built as an integated amp 300va 2x25v
The chassis was a scratch built by me from aluminium with a temp Corian front panel before i get a 10mm aluminium plate CNC machined.
The 48mm Volume knob was souced on Ebay from seller 8audio based in china but delivery was quick .
I would just like to thank Peter for all his help on the forum
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I wrote a quick and dirty guide below for bending aluminium if anyones interested in making their own chassis
http://bit.ly/d7ayVE
Have fun
Rupert