Dear A19 builders,
I must say that I haven't build an A19 yet, still collecting parts and looking for some adequate heatsinks and housing.
It's quiet on this subject, is anyone else building an A19 or have finished one yet ?
Love to hear some comments. And some foto's please.
Hope to hear from you soon.
Jurjen from a wet Holland
I must say that I haven't build an A19 yet, still collecting parts and looking for some adequate heatsinks and housing.
It's quiet on this subject, is anyone else building an A19 or have finished one yet ?
Love to hear some comments. And some foto's please.
Hope to hear from you soon.
Jurjen from a wet Holland
I abandoned the project after the 1st board was released with so many errors and inadequate documentation.
Again have to disagree with Garry on that. The demands of Garry could not be met and i decided not to supply further pcb’s to him.
The current board performs very well and with no errors.
The current board performs very well and with no errors.
To correct you Marcel, I decided not to go ahead - you contacted me to ask if I wanted to buy the new version.
That was an offer to replace the boards with errors. Not going to further discuss this.
Those who can build this amp will find a stunning performance.
Did an A/B test with F4, F5 and Aleph 30. This amp outperforms all in clarity, dark background and dynamics.
Thank you Hawk and John van der Sluis (rip)
The choice is up to you all.
Those who can build this amp will find a stunning performance.
Did an A/B test with F4, F5 and Aleph 30. This amp outperforms all in clarity, dark background and dynamics.
Thank you Hawk and John van der Sluis (rip)
The choice is up to you all.
Hi Tarasque,
In bridge mode like you're assembling them, I guess you cannot go lower than 8 ohms load? What's that power you get in bridge mode? Lastly, which transistors have to be matched?
Thanks
Do
In bridge mode like you're assembling them, I guess you cannot go lower than 8 ohms load? What's that power you get in bridge mode? Lastly, which transistors have to be matched?
Thanks
Do
In bridgemode the total dissipation of the power fets is leading and I would not go beond 35W per fet. This gives a maximum of ~300W dissipation. The amplifier is unconditionaly stable for all loads down to 1 ohm. With 2 parallel fets I would not go above an output current of 14 amp's and I have fused my builds accordingly. In any case the power supply needs to be able to deliver the current for lower impedances.
I have used 600VA (18-0-18V) toroids and with that supply is is possible to deliver ~160W output power.
This amplifier topology would allow to put more fets in parallel like is used in other designs of Hawk and that would allow to address lreally low impedances.
Also in this design there are no devider resistors to spread the current over the number of parallel fets. Therefor I have matched on both Vgs and Gm parameters for optimum performance.
I use P and N transistors from the same wafer to optimize the input and the offset circuits.
I have used 600VA (18-0-18V) toroids and with that supply is is possible to deliver ~160W output power.
This amplifier topology would allow to put more fets in parallel like is used in other designs of Hawk and that would allow to address lreally low impedances.
Also in this design there are no devider resistors to spread the current over the number of parallel fets. Therefor I have matched on both Vgs and Gm parameters for optimum performance.
I use P and N transistors from the same wafer to optimize the input and the offset circuits.
Hi I'm looking for a Hawk A18 amplifier kit, reviewed on TNT Audio. With the possibility to choose the operating class from AB to A. Can anyone provide me with the PCBs and main components?
Thank you
Thank you
Yes I can. I have build and tested ones of the A18 and A19 as well as the pcb’s and fets.
How many channels do you need?
How many channels do you need?
Hi Tarasque, I just read this very interesting blog. I have an A15 which I really like. Only thing is that it somehow triggers my tinnitus. So that's not a good thing of course. To get away from my complaint I recently bought an A18 readily build according the original kit. Unfortunately I'm disappointed with the sound. It sounds shut in and liveless. Do you have any idea what the course could be?
It depends on the version of A18 that you have. Beside that there is a sonic difference between the Hitachi and the Exicon fets. I prefer the latter. The A18 uses 2 parallel fets and it is important to select the fets for equal Gm and Ugs.
Also the comercial A18 still uses the L78 and 7911 to regulate the frontend as well as the servo. In the later version the frontend is powered with a lownoise discrete regulation and the servo uses zeners for 15v supply.
This greatly helps the openness of the sound.
Also the supply caps are playing a role.
Regards…
Also the comercial A18 still uses the L78 and 7911 to regulate the frontend as well as the servo. In the later version the frontend is powered with a lownoise discrete regulation and the servo uses zeners for 15v supply.
This greatly helps the openness of the sound.
Also the supply caps are playing a role.
Regards…
Hi Marcel,
Thanks for your reply.
I have the original one with the original prints.
Like I sad, The A15 plays much better. But probably also the caps need replacement. Could the course of the trigger on my tinnitus be some kind of distortion?
Maybe It's better to build your version. Do you still have prints?
Regards,
Dick
Thanks for your reply.
I have the original one with the original prints.
Like I sad, The A15 plays much better. But probably also the caps need replacement. Could the course of the trigger on my tinnitus be some kind of distortion?
Maybe It's better to build your version. Do you still have prints?
Regards,
Dick