Add me to the list for a complete set of Yarra PCBs whenever the order materializes. I want to build another PSU with lower voltages.
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Thank you sir! I will let you know, mine has the Alps in there now two and it sounds fine. I had a TKD from another build installed it and damned if one channel didn't start cutting out.
When you get to the volume pcb, best to get some 22ga wire and wire between the Yarra pcb and the volume. Also, if you are using the purpose built Yarra case you will need to bore the counter a lot more to get enough threads to start the nut on the pot.
When you get to the volume pcb, best to get some 22ga wire and wire between the Yarra pcb and the volume. Also, if you are using the purpose built Yarra case you will need to bore the counter a lot more to get enough threads to start the nut on the pot.
Yarra GB2 interest list:
xrk971 2 board sets USA
musical 1 board set USA
redjr 1 board set USA
I will ask JPS64 if he can break out the PSU in the Yarra as a standalone board.
It’s perhaps the state of the art linear PSU for any preamp or headphone amp project.
Will be very useful for other projects. I want to use it on my parallel 8x OPA1622 headphone amp.
xrk971 2 board sets USA
musical 1 board set USA
redjr 1 board set USA
I will ask JPS64 if he can break out the PSU in the Yarra as a standalone board.
It’s perhaps the state of the art linear PSU for any preamp or headphone amp project.
Will be very useful for other projects. I want to use it on my parallel 8x OPA1622 headphone amp.
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Do me a favor and see what kind of effort it would take to move that header for the headphone as mentioned earlier. I don't know if you saw it, but the placement really limits the size of the caps on the left of the PCB.
Also, there is an issue with the volume pcb. If the board could be shortened (front side where pot is mounted) where it makes contact with the face of the chassis it would help in two ways. First, we already have an issue with the pot shaft threads being long enough to get through the front of the chassis. This would help that. The other is the pcb sticks out from the pot a good 1/8 or so. In other words, you can not draw it up because it cants the pcb unless you have a spacer to take up that 1/8th inch, but you don't want to do that because that's a 1/8 of threads that could be used to help with the chassis plate thickness and the lack of threads.
If any of this doesn't make sense, I will post some pics of what I'm talking about.
JP did a fantastic job on this thing and there's noway to foresee every possible hick-up. If it's not a great deal of work, I think these points will help others down the line. I know I will be building another Yarra as well.
JT
Also, there is an issue with the volume pcb. If the board could be shortened (front side where pot is mounted) where it makes contact with the face of the chassis it would help in two ways. First, we already have an issue with the pot shaft threads being long enough to get through the front of the chassis. This would help that. The other is the pcb sticks out from the pot a good 1/8 or so. In other words, you can not draw it up because it cants the pcb unless you have a spacer to take up that 1/8th inch, but you don't want to do that because that's a 1/8 of threads that could be used to help with the chassis plate thickness and the lack of threads.
If any of this doesn't make sense, I will post some pics of what I'm talking about.
JP did a fantastic job on this thing and there's noway to foresee every possible hick-up. If it's not a great deal of work, I think these points will help others down the line. I know I will be building another Yarra as well.
JT
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X - Have you given any thought to a Yarra Pre Ver 2? Here's my wish list;
o - 12v Trigger w/delay
o - Single, Summed Channel Sub-Out
o - Both Balanced and Unbalanced I/O.
o - Motorized Volume control w/remote
o - Two-line LED display showing Source and Volume level.
o - Mute Control
o - Selectable MM/MC Phono stage with adjustable gain.
o - Build price <$500 (excluding case)
Just some New Year's wishes. Just asking
I need a new Spring project.
Hi X,
Since we are talking about a possible Yarra psu revision, my request would be to make it regulated. That will give more voltage options for a given set of transformers (within reason of course). Also, it would keep the preamp in its sweet spot no matter what household appliance cycles or mains fluctuations.
My mains voltage varies quite a bit season to season, night and daytime. On hot summer days I have recorded a 13vac swing morning to night.
I would use this psu for other regulated low current projects also, like a Dac.
Since we are talking about a possible Yarra psu revision, my request would be to make it regulated. That will give more voltage options for a given set of transformers (within reason of course). Also, it would keep the preamp in its sweet spot no matter what household appliance cycles or mains fluctuations.
My mains voltage varies quite a bit season to season, night and daytime. On hot summer days I have recorded a 13vac swing morning to night.
I would use this psu for other regulated low current projects also, like a Dac.
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We will look at a Yarra V2 but it’s off in the future. The GB2 I am asking people for interest now is an identical board to what has been shipped thus far. The Yarra layout is not easy to modify as changing one thing moves other things and there are lots of vias to manually add again.
Couple of things we are already looking at:
Balanced in and out but realize that it will mean the balanced goes through a THAT based specific opamp converter. MCU controlled turn on delay and digital volume control, Bluetooth input capability, phono stage input,...
A regulated PSU might be a good idea. For the separate psu I meant that it would be identical - minimal layout work. To make it regulated would be a new board basically
Keep the ideas ideas coming..
Couple of things we are already looking at:
Balanced in and out but realize that it will mean the balanced goes through a THAT based specific opamp converter. MCU controlled turn on delay and digital volume control, Bluetooth input capability, phono stage input,...
A regulated PSU might be a good idea. For the separate psu I meant that it would be identical - minimal layout work. To make it regulated would be a new board basically
Keep the ideas ideas coming..
I decided to swap out my 15 volt transformers for 22 volt. I wanted 18 volt but Digikey is out until May. I set the power supply voltage drop to 4 volts, but I am at about 29.8 volts at the Melbourne boards. X mentioned that the Melbournes were designed for 24 volts. Am I causing any harm running them up so high?
Verical/Arrow has them:
https://www.verical.com/pd/on-semic...ampaign=digipart_2018&utm_content=inv_listing
Also, not that critical. Any similar small signal TO92 PNP with same pin out will work.
https://www.verical.com/pd/on-semic...ampaign=digipart_2018&utm_content=inv_listing
Also, not that critical. Any similar small signal TO92 PNP with same pin out will work.
Hi Folks,
Just want to let you know I have a new batch of PCA daughterboards for the Yarra. These are green solder mask and gold ENIG finish. They sound exceptionally good - classic SE Class A harmonic profile using JFET input and MOSFET source follower output. Can use 2sk209BL, 2sk170BL, or BF862. Can also be reconfigured for GR JFETs - will require some resistor changes. Uses any TO220 N channel MOSFET such as IRF610, Fairchild equivalent, or even Toshiba 2SK2013’s if you have them. One of the best sounding preamps and only 2 transistors.
PCA Daughterboard for Yarra Preamp | Etsy
Just want to let you know I have a new batch of PCA daughterboards for the Yarra. These are green solder mask and gold ENIG finish. They sound exceptionally good - classic SE Class A harmonic profile using JFET input and MOSFET source follower output. Can use 2sk209BL, 2sk170BL, or BF862. Can also be reconfigured for GR JFETs - will require some resistor changes. Uses any TO220 N channel MOSFET such as IRF610, Fairchild equivalent, or even Toshiba 2SK2013’s if you have them. One of the best sounding preamps and only 2 transistors.
PCA Daughterboard for Yarra Preamp | Etsy
Not needed, but it gives them stability. I soldered one leg only, just to make then less likely to vibrate. I only comment because I read it somewhere in the posts, not because I know anything.