I'm done, I'm happy with the sound. All I have to do now is to fit the sturdy Dynavox feet on the bottom lid.
I've listened to different genres (techno, hardstyle, pop, rock), the bass is stunning, the vocals are crystal clear...
I've listened to different genres (techno, hardstyle, pop, rock), the bass is stunning, the vocals are crystal clear...
Attachments
Here is new layout with Molex connection and R32 removed and replaced with short connection.
Molex socket https://www.tme.eu/hr/details/mx-22-04-1031/konektori-signalni-raster-2-50mm/molex/22-04-1031/
Molex plug wire-board https://www.tme.eu/hr/details/mx-22-01-1032/konektori-signalni-raster-2-50mm/molex/22-01-1032/
Molex socket https://www.tme.eu/hr/details/mx-22-04-1021/konektori-signalni-raster-2-50mm/molex/22-04-1021/
Molex plug wire-board https://www.tme.eu/hr/details/mx-22-01-1022/konektori-signalni-raster-2-50mm/molex/22-01-1022/
With my PCB no need for two mains transformer, one is enough to get full dual mono configuration.
Have a nice build.
Damir
Molex socket https://www.tme.eu/hr/details/mx-22-04-1031/konektori-signalni-raster-2-50mm/molex/22-04-1031/
Molex plug wire-board https://www.tme.eu/hr/details/mx-22-01-1032/konektori-signalni-raster-2-50mm/molex/22-01-1032/
Molex socket https://www.tme.eu/hr/details/mx-22-04-1021/konektori-signalni-raster-2-50mm/molex/22-04-1021/
Molex plug wire-board https://www.tme.eu/hr/details/mx-22-01-1022/konektori-signalni-raster-2-50mm/molex/22-01-1022/
With my PCB no need for two mains transformer, one is enough to get full dual mono configuration.
Have a nice build.
Damir
Attachments
Hi Damir, BIG THANKS!
I'm going to redo the whole thing, it's going to look so much better, ...less cable connections.
I don't have enough BC560 anymore, Damir what replacement to choose? BC547/BC557 or BC327-40/BC337-40?
I'm going to redo the whole thing, it's going to look so much better, ...less cable connections.
I don't have enough BC560 anymore, Damir what replacement to choose? BC547/BC557 or BC327-40/BC337-40?
Late I noticed the pcb contains a bug. The boards are already in production and I can throw them in the trash.
I'm done here, ...I'm going to DCG3
Attachments
Q23 at the top (bd 139 is outside the heat sink)
correction on silkscreen: C4 at the top is wrong 2200uF should be 220uF
correction on silkscreen: C4 at the top is wrong 2200uF should be 220uF
I am very sorry, was in hurry to add molex connectors and by accident moved that transistor.
You don't need to throw the boards just drill to new holes for Q23 and some intervention on the tracks it should be OK.
Sorry Damir
Regarding C4 and C11 not critical, you can also use 100 uF in those positions.
You don't need to throw the boards just drill to new holes for Q23 and some intervention on the tracks it should be OK.
Sorry Damir
Regarding C4 and C11 not critical, you can also use 100 uF in those positions.
Attachments
It will be very good to use KSC992/KSA1845 as replacement for obsolete BC550C/BC560C.
Again put spice models for KSC/KSA modify schematic to work with these BJT and make new pcb layout as these new BJT have different pinout.
As for now as is members don't get very much interested in obsolete parts. You can use BC549C/BC559C but for how long? Until stock get sold put.
For output devices use can use slow BD139/BD140 or faster KSC1381/KSA3503 that you can buy at mouser with lower Cob.
So question for daddod, can you simulate again in LTspice with new bjt models and post schematic so that interested members can make new pcb with new pinout for new used bjt?
If not, this preamp will be very quickly forgotten and abandonen as diy members can source any more used in simulatoon old bjt parts.
Thanks for great design Damir!
Again put spice models for KSC/KSA modify schematic to work with these BJT and make new pcb layout as these new BJT have different pinout.
As for now as is members don't get very much interested in obsolete parts. You can use BC549C/BC559C but for how long? Until stock get sold put.
For output devices use can use slow BD139/BD140 or faster KSC1381/KSA3503 that you can buy at mouser with lower Cob.
So question for daddod, can you simulate again in LTspice with new bjt models and post schematic so that interested members can make new pcb with new pinout for new used bjt?
If not, this preamp will be very quickly forgotten and abandonen as diy members can source any more used in simulatoon old bjt parts.
Thanks for great design Damir!
Next step is to use SMD parts, but I don't have time now to design completely new layout.
Thanks for the great design Damir! I really appreciate the gerbers you have shared also.
I have a request, can you please share only the pre-amp part of the board (gerbers) separately, without the power-supply. It would be of great help to me.
I have designed only this PCB with preamp and power supply ingreted and not separate preamp, sorry. This preamp is designed to work best with this power supply.
I could in future design the new board with SMD parts, I finnished with trough hole parts.
I could in future design the new board with SMD parts, I finnished with trough hole parts.
Hello Damir,
Is it possible to use 2x 18v transformer for this design? And, is it okay to use 50K volume control, instead of 10K as in the schematics?
Thanks!
Is it possible to use 2x 18v transformer for this design? And, is it okay to use 50K volume control, instead of 10K as in the schematics?
Thanks!
Hi, I want to fit the new GainWire board with better resistors than the prototype above, but I don't know if it makes sense? The prototype was fitted with ordinary YEGEO resistors, and no noise was audible, now the question is whether it makes sense to use Vishay MRS25 or RN55/CMF55 low-noise resistors on the new board?
I already have the boards at home, expecting the parts from digikey at the beginning of the week. I have decided that I will only do this GainWire MK3 (CFA) and it will be part of a large integrated amplifier in a 5U modushop box. I really like the sound of this GainWire MK3, and I have to listen to it (until I'm completely deaf) not just build new ones over and over again...
For dimensional reasons I have to use heat sinks with a length of 38mm (11K/W). The 50.8mm long heatsinks reached a temperature of about 30°C (9K/W).
The input switching will be from Salas (I-Select), which already has it on the way. Above the filter capacitors will be the inner pierced base will still be adjusted to the required size.
For dimensional reasons I have to use heat sinks with a length of 38mm (11K/W). The 50.8mm long heatsinks reached a temperature of about 30°C (9K/W).
The input switching will be from Salas (I-Select), which already has it on the way. Above the filter capacitors will be the inner pierced base will still be adjusted to the required size.
