Wayne's BA 2018 line stage completed
This is the follow-on to posts #619 https://www.diyaudio.com/forums/pass-labs/329240-waynes-ba-2018-linestage-62.html#post5763554 and #681 https://www.diyaudio.com/forums/pass-labs/329240-waynes-ba-2018-linestage-69.html#post5777341.
After my transformer had arrived from Toroidy, I could go and finish the PSU.
I have built a separate PSU, connected with an umbilical to the preamp case.
For the PSU, I used a Modushop Galaxy 2H case.
As discussed, I put the boards for Wayne's linestage into a "passive preamp" case I bought via eBay, complete with relay volume control and remote control for volume and inputs, The transformer I had removed from that case and put into the PSU (front left), together with a generic regulated PSU to bring something like +15V to the preamp for powering the relays and control circuitry.
Top left in the PSU case in the photo is a Schurter line filter – the 0.6A version, as that has better performance with low mains current draw then the higher-current versions.
For the main PSU to power the boards, I bought a kit from eBay that uses a pass MOSFET and error amplifier per rail. This is powered from a 2x24V transformer.
The preamp itself has a headphone output in parallel - no need for a switched headphone jack, as I could simply leave the power amp switched off.
After adjusting voltages I could get the voltage offset down to a couple mV. (preamp has to be completely warmed up for that, as usual). AC on the outputs below 0.1 mV (my DMM stated 0.07-0.08 mV, but I think that is too close to the limits of the DMM to be accurate).
This is how the preamp looks in the system:
So, how does it sound ?
First, it has a turn-on thump (capacitor-coupled outputs), but no switch-off noise. In use, it is complety silent over my 100 db/W loudspeakers - no hum, no noise.
It sounds very good to me - lots of information, good staging, very transparent, balanced, but also engaging. Voices have this quality to stop you in your tracks and make you drop everything else just to listen.
What's interesting is that when I compare the sound, my Aikido linestage (E80CC / 6N6P) has a bit more high-frequency detail / content.
When measured on my oscilloscope, Wayne's linestage is clean and flat out into the MHz range (my signal generator stops at 2 MHz, and there the linestage still has not reached its -3dB point).So I don't really know what's responsible for this.
Can't decide if I like my Aikido more or this linestage - need to listen way more ...
What will be next: I plan to do distortion measurements with the current set-up, and then exchange the output transistors (2SA1220 / 2SC2690 from Inchange Semi) for Toshiba TTA004C and TTB004C (as per the tip from Patrick / EUVL).
Best regards, Claas
This is the follow-on to posts #619 https://www.diyaudio.com/forums/pass-labs/329240-waynes-ba-2018-linestage-62.html#post5763554 and #681 https://www.diyaudio.com/forums/pass-labs/329240-waynes-ba-2018-linestage-69.html#post5777341.
After my transformer had arrived from Toroidy, I could go and finish the PSU.
I have built a separate PSU, connected with an umbilical to the preamp case.
For the PSU, I used a Modushop Galaxy 2H case.
As discussed, I put the boards for Wayne's linestage into a "passive preamp" case I bought via eBay, complete with relay volume control and remote control for volume and inputs, The transformer I had removed from that case and put into the PSU (front left), together with a generic regulated PSU to bring something like +15V to the preamp for powering the relays and control circuitry.
Top left in the PSU case in the photo is a Schurter line filter – the 0.6A version, as that has better performance with low mains current draw then the higher-current versions.
For the main PSU to power the boards, I bought a kit from eBay that uses a pass MOSFET and error amplifier per rail. This is powered from a 2x24V transformer.
The preamp itself has a headphone output in parallel - no need for a switched headphone jack, as I could simply leave the power amp switched off.
After adjusting voltages I could get the voltage offset down to a couple mV. (preamp has to be completely warmed up for that, as usual). AC on the outputs below 0.1 mV (my DMM stated 0.07-0.08 mV, but I think that is too close to the limits of the DMM to be accurate).
This is how the preamp looks in the system:
So, how does it sound ?
First, it has a turn-on thump (capacitor-coupled outputs), but no switch-off noise. In use, it is complety silent over my 100 db/W loudspeakers - no hum, no noise.
It sounds very good to me - lots of information, good staging, very transparent, balanced, but also engaging. Voices have this quality to stop you in your tracks and make you drop everything else just to listen.
What's interesting is that when I compare the sound, my Aikido linestage (E80CC / 6N6P) has a bit more high-frequency detail / content.
When measured on my oscilloscope, Wayne's linestage is clean and flat out into the MHz range (my signal generator stops at 2 MHz, and there the linestage still has not reached its -3dB point).So I don't really know what's responsible for this.
Can't decide if I like my Aikido more or this linestage - need to listen way more ...
What will be next: I plan to do distortion measurements with the current set-up, and then exchange the output transistors (2SA1220 / 2SC2690 from Inchange Semi) for Toshiba TTA004C and TTB004C (as per the tip from Patrick / EUVL).
Best regards, Claas
Attachments
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I don't know the answer. But I have an idea which might help you figure out the answer yourself.
The schematic attached to post #1 of this thread, includes resistor "R23" whose value is 330 ohms. There is no other 330 ohm resistor on the schematic. Only R23.
You might be able to look at the Mouser cart BOM of this thread, and count up how many 330 ohm resistors it includes. If the answer is one, you know it's for a single board. If the answer is two, you know it's for a pair of boards (stereo). If the answer is more than two, something very weird is going on!
I believe 6L6 created that BOM and if its the same one I used it was parts for both boards. To be on the safe side Id check with 6L6.
Hi Jean-Paul,
I think now we have confused everyone ...
TTA004B,Q and TTC004B,Q
Regards,
Claas
For those who may be interested in having a nice state of the art PSU, motherboard, and case for Wayne’s 2017 BA linestage preamp, JPS64 has developed a nice implementation in mostly TH as a small Yarra-compatible daughterboard. We are just gauging interest at this point, but the Yarra is a full featured system with modular preamp cores that are swappable. The default core is the superb Aksa-Lender based Melbourne. However, we are considering other topologies as they come up and the motherboard provides a nice easy to use swappable environment for “preamp rolling”. More info here:
The YARRA Preamplifier/HPA for Melbourne DB Group Buy
This is Wayne’s 2017 BA Linestage in Yarra compatible format:
These would fit on the Yarra motherboard and PSU system:
Which also has a custom HiFi2000 Yarra case (only 100 Euro) to go with it, if you happened to get one of those already as the GB closed. However, with sufficient interest in the cases, another round could happens. More info on the case here:
YARRA Preamplifier Custom Case at Modushop
Btw, Yarra is nicely fitted with lots of pads for input and output caps of all sizes, including huge boutique caps. These can be jumpered for DC coupled operation of course. Plus a 4 way rotary input selector switch.
The YARRA Preamplifier/HPA for Melbourne DB Group Buy
This is Wayne’s 2017 BA Linestage in Yarra compatible format:
These would fit on the Yarra motherboard and PSU system:
Which also has a custom HiFi2000 Yarra case (only 100 Euro) to go with it, if you happened to get one of those already as the GB closed. However, with sufficient interest in the cases, another round could happens. More info on the case here:
YARRA Preamplifier Custom Case at Modushop
Btw, Yarra is nicely fitted with lots of pads for input and output caps of all sizes, including huge boutique caps. These can be jumpered for DC coupled operation of course. Plus a 4 way rotary input selector switch.
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For those who may be interested in having a nice state of the art PSU, motherboard, and case for Wayne’s 2017 BA linestage preamp, JPS64 has developed a nice implementation in mostly TH as a small Yarra-compatible daughterboard. We are just gauging interest at this point, but the Yarra is a full featured system with modular preamp cores that are swappable. The default core is the superb Aksa-Lender based Melbourne. However, we are considering other topologies as they come up and the motherboard provides a nice easy to use swappable environment for “preamp rolling”. More info here:
The YARRA Preamplifier/HPA for Melbourne DB Group Buy
This is Wayne’s 2017 BA Linestage in Yarra compatible format:
These would fit on the Yarra motherboard and PSU system:
Which also has a custom HiFi2000 Yarra case (only 100 Euro) to go with it, if you happened to get one of those already as the GB closed. However, with sufficient interest in the cases, another round could happens. More info on the case here:
YARRA Preamplifier Custom Case at Modushop
Btw, Yarra is nicely fitted with lots of pads for input and output caps of all sizes, including huge boutique caps. These can be jumpered for DC coupled operation of course. Plus a 4 way rotary input selector switch.
Me likey. I'll take a pair when they become available.
Russellc
Slight update to Wayne’s BA module for Yarra, now with some more local rail smoothing caps.
Also attached is updated schematic.
Note that this might be useful/interesting/fun to try inside the M2X as well.
Also attached is updated schematic.
Note that this might be useful/interesting/fun to try inside the M2X as well.
Attachments
Last edited:
Slight update to Wayne’s BA module for Yarra, now with some more local rail smoothing caps.
Also attached is updated schematic.
Note that this might be useful/interesting/fun to try inside the M2X as well.
Hi Wayne,
We have received several replies for people interested in a Yarra-compatible Wayne’s 2017 BA input stage board (mostly from the Yarra thread). Just want to check with you if you are good with us to proceed offering this board as a GB.
Thanks,
xrk971
@Zen Mod
To use Wayne´s BA18 preaamplifier you need a power supply so I´ve found cool to use the YARRA one then already tested. And why not using YARRA mainboard, perhaps someone would use the design in the M2X?
So I´ve started faisability doing successfully SMD layout. Why not, then a lot of guys prefer THT, the THT version? Fits, cool (all explained modifications included).
Next, then work is achieved, proposing this to the DIY community?
No Owner approval, no PCB GB and I´ll build one for my own "plaisir".
@6L6
Yes!
JP
To use Wayne´s BA18 preaamplifier you need a power supply so I´ve found cool to use the YARRA one then already tested. And why not using YARRA mainboard, perhaps someone would use the design in the M2X?
So I´ve started faisability doing successfully SMD layout. Why not, then a lot of guys prefer THT, the THT version? Fits, cool (all explained modifications included).
Next, then work is achieved, proposing this to the DIY community?
No Owner approval, no PCB GB and I´ll build one for my own "plaisir".
@6L6
Yes!
JP
As a bit of data, here is the interest list for JPS64's design:
There are many ways to start projects in the commercial world. Often feasibility studies, list of willing customers, completed initial designs are often submitted as part of a proposal to show how ready a project is to proceed to the next level. Those are usually the ones selected because they show a thoughtful state of the art design, a solid well-prepared team that can execute, plus a list of willing and ready customers. Granted, this is DIY and not commercial, but the process can be similar in many ways. We are very lucky in DIYA to have someone with JPS64's experience providing us with these nice designs.
There are many ways to start projects in the commercial world. Often feasibility studies, list of willing customers, completed initial designs are often submitted as part of a proposal to show how ready a project is to proceed to the next level. Those are usually the ones selected because they show a thoughtful state of the art design, a solid well-prepared team that can execute, plus a list of willing and ready customers. Granted, this is DIY and not commercial, but the process can be similar in many ways. We are very lucky in DIYA to have someone with JPS64's experience providing us with these nice designs.
