I'm wondering if anyone has tried the Burson opamps in place of the stock ones? If so, what were your impressions?
Thank you RJM.
Ok moving on to the transformer casing are there any do's or don'ts that I should be aware of? I recall your recommendation of twisting all wiring (except mains earth) but is there anything else? Spacing of the transformer and DBRB board for example? Also is it ok to add an LED into the transformer case? If so, wired from the rectified side of the board? 240V mains-in spaced away from the DC out wires is another question?
Many thanks.
Ok moving on to the transformer casing are there any do's or don'ts that I should be aware of? I recall your recommendation of twisting all wiring (except mains earth) but is there anything else? Spacing of the transformer and DBRB board for example? Also is it ok to add an LED into the transformer case? If so, wired from the rectified side of the board? 240V mains-in spaced away from the DC out wires is another question?
Many thanks.
Well this is the layout of the transformer case... it doesn't seem like there are many other options to an inexperienced eye anyway. The only other thought I had was an aluminium divider (easy enough to do) if it offers any overall benefit?
Since the power supply doesn't carry signal, there really isn't much to worry about except safety and not mixing up the positive and negative connections.
Seems like you have everything well in hand. What is the yellow connector for the power umbilical? Is it XLR?
Attachments
I have built the Emerald and more recently the Sapphire Headphone amplifier.
For testing I used a single 32va transformer.
Now that I am about to move all the boards to a rack mount chassis I thought to improve the power supply and connections..
I installed dual 32 va transformers with single bridges and canon connectors....
Wow!.... there is just no comparison....it's like I upgraded from a $500 circuit to a $5000 circuit....
Now playing lp after lp..... 🙂
(Where is that copy of Roger the Engineer...he said looking hopefully at 10,000 un-categorised LPs 😱)
For testing I used a single 32va transformer.
Now that I am about to move all the boards to a rack mount chassis I thought to improve the power supply and connections..
I installed dual 32 va transformers with single bridges and canon connectors....
Wow!.... there is just no comparison....it's like I upgraded from a $500 circuit to a $5000 circuit....
Now playing lp after lp..... 🙂
(Where is that copy of Roger the Engineer...he said looking hopefully at 10,000 un-categorised LPs 😱)
Hello Richard,
The Emerald looks like just what I need to replace my current phono preamp. Just a quick question; would there be any detriments with wiring JP1 to a switch on the chassis to make for easy/quick switching between MM and MC?
The Emerald looks like just what I need to replace my current phono preamp. Just a quick question; would there be any detriments with wiring JP1 to a switch on the chassis to make for easy/quick switching between MM and MC?
That's a viable option. Just try to keep the wiring short and carefully twisted together to reduce the possibility of interference.
Thank you very much for the quick reply and for confirming what I thought. I would also guess that your suggestion for the wiring applies to the switchboard as well.
Thanks again!
Thanks again!
Hi Richard,
I am thinking of building the Emerald and have a some questions. This will be an MM only implementation.
I have a few MM cartridges that range from 1.3mV to 4.5mV output. The low output cartridge will need about 47dB gain. It looks like changing R3 to a higher value would lower the 57dB gain. I am correct here.
Can the 47k be changed to say 100k without effecting performance.
cheers
I am thinking of building the Emerald and have a some questions. This will be an MM only implementation.
I have a few MM cartridges that range from 1.3mV to 4.5mV output. The low output cartridge will need about 47dB gain. It looks like changing R3 to a higher value would lower the 57dB gain. I am correct here.
Can the 47k be changed to say 100k without effecting performance.
cheers
If you want to set two gain settings for MM range, that's no problem. Let's say 37 dB and 47 dB. You'd change R3 to 330 ohms,
R1 100 kohms
R2 86 kohms
R3 330 ohms
R4 1500 ohms
R5 1500 ohms
This gives 37 and 47 dB gain, and 100k and 47k input loading.
R1 100 kohms
R2 86 kohms
R3 330 ohms
R4 1500 ohms
R5 1500 ohms
This gives 37 and 47 dB gain, and 100k and 47k input loading.
Hi Richard: I'm debugging my setup; maybe you have a quick idea?
I put together the Emerald - it works fine, but there is a very audible hum (even at 5% volume) whenever I connect the phono stage to the turntable. Grounding does not help, nor lifting the grounds of amp/phono stage with a cheater plug. The hum disappears if I unplug one of the channels from turntable to phono stage.
I put together the Emerald - it works fine, but there is a very audible hum (even at 5% volume) whenever I connect the phono stage to the turntable. Grounding does not help, nor lifting the grounds of amp/phono stage with a cheater plug. The hum disappears if I unplug one of the channels from turntable to phono stage.