Hi Andrew,
It appears your hifisonix website is currently down! Hope you can fix it soon!
Best,
Anand.
It appears your hifisonix website is currently down! Hope you can fix it soon!
Best,
Anand.
For a few days now there have been 2 errors:
1. "There has been a critical error on your website."
Hitting 'refresh sometimes helps to go to the site but then changing pages again sometime one gets the same error.
2. "Unable to access Database" (or similar)
Error repeats even on attempting to refresh the page.
Hope you can get it sorted out.
Best,
1. "There has been a critical error on your website."
Hitting 'refresh sometimes helps to go to the site but then changing pages again sometime one gets the same error.
2. "Unable to access Database" (or similar)
Error repeats even on attempting to refresh the page.
Hope you can get it sorted out.
Best,
Hi guys
Yes I am having a lot of problems since I installed PHP 7.3 (required for compatibility reasons) and I am still struggling to take the site across to https.
It’s back up now. If you get the error, hit the refresh button on your browser.
It may still be on and off for a while, but it will get sorted. Any technical questions, feel free to PM me here in the interim.
Yes I am having a lot of problems since I installed PHP 7.3 (required for compatibility reasons) and I am still struggling to take the site across to https.
It’s back up now. If you get the error, hit the refresh button on your browser.
It may still be on and off for a while, but it will get sorted. Any technical questions, feel free to PM me here in the interim.
If you go to the 'ground loops' link you may be able to navigate the site from there. I was able to yesterday.
Edit: ...but not just now!
@ Andrew....
I am now able to type a little though still on steroids& morphine cocktail therefore may not make too much sense!!! Nevertheless I will be in touch soon re NX PS problems!!!
Edit: ...but not just now!
@ Andrew....
I am now able to type a little though still on steroids& morphine cocktail therefore may not make too much sense!!! Nevertheless I will be in touch soon re NX PS problems!!!
Last edited:
Anyone compared the sound between class A and AAB.
I have 2x25ac transformer and would like to try this amp.
I have 2x25ac transformer and would like to try this amp.
I can switch mine between class A and class AAB. The sound is very smooth and warm in either position.
You will need very good speakers and a good recording to tell the difference IMV.
You will need very good speakers and a good recording to tell the difference IMV.
For the small extra cost, I'd say its a worth while upgrade.
With 25 VAC transformer secondaries you will get about 50 Watts of class AAB.
Just remember to use filter capacitors in the PSU rated for the worst case secondary voltage - so 40V will be about right - I think 35V might be a bit risky. with Class AAB and a ripple eater you can go for 15 000 uF to 22 000 uF caps.
With 25 VAC transformer secondaries you will get about 50 Watts of class AAB.
Just remember to use filter capacitors in the PSU rated for the worst case secondary voltage - so 40V will be about right - I think 35V might be a bit risky. with Class AAB and a ripple eater you can go for 15 000 uF to 22 000 uF caps.
Have received my amp boards ex Jims and currently stuffing them.
The amps will be run in class AAB only via a 35 V PSU so will 0.38 °C/W heatsinks (one per channel) suffice?
C15 270pF I can only get Silver Mica in that value, hope that's OK?
R16/R17 (15R) are suggested at 1/2W, would 1/4W be OK (because I have to use 50V caps at 12.5mm diameter, not 10mm, for the 35V supply and trying to make a little more space to fit them) i.e. C6, C7, C8, C13 @ 1,000uF
Q3 (KSA1381) and Q4 (KSC3503) will use 'as is' but have to purchase tubes of 60 each (min from supplier - RS) but luckily not too expensive and will probably be useful later on.
For the moment Q10/Q11 will try BD139-16/BD140-16 as I have in my stock.
Q8/Q9 at least I can get in pack sizes of 5 by NJW1302G and 2 by NJW3281G from RS but will also try one channel using 2SC3264/2SA1295 (ex my stock) on a 'test bed' and see what happens and let you know.
As per Page 15 of 24/01/17 PDF:
Only 5 paralleled 1K8 resistors (R26 - R30) are shown but there are 6 on the PCB (and P16 Overlay) so one more per channel needs adding to the BOM. Will this also change the 'gain' settings with R25 values as indicated on Page 15 (assuming only 5 by 1k8 were used in the calculation)?
P.S. Many thanks for the project and sorry for the '100 questions'.
The amps will be run in class AAB only via a 35 V PSU so will 0.38 °C/W heatsinks (one per channel) suffice?
C15 270pF I can only get Silver Mica in that value, hope that's OK?
R16/R17 (15R) are suggested at 1/2W, would 1/4W be OK (because I have to use 50V caps at 12.5mm diameter, not 10mm, for the 35V supply and trying to make a little more space to fit them) i.e. C6, C7, C8, C13 @ 1,000uF
Q3 (KSA1381) and Q4 (KSC3503) will use 'as is' but have to purchase tubes of 60 each (min from supplier - RS) but luckily not too expensive and will probably be useful later on.
For the moment Q10/Q11 will try BD139-16/BD140-16 as I have in my stock.
Q8/Q9 at least I can get in pack sizes of 5 by NJW1302G and 2 by NJW3281G from RS but will also try one channel using 2SC3264/2SA1295 (ex my stock) on a 'test bed' and see what happens and let you know.
As per Page 15 of 24/01/17 PDF:
Only 5 paralleled 1K8 resistors (R26 - R30) are shown but there are 6 on the PCB (and P16 Overlay) so one more per channel needs adding to the BOM. Will this also change the 'gain' settings with R25 values as indicated on Page 15 (assuming only 5 by 1k8 were used in the calculation)?
P.S. Many thanks for the project and sorry for the '100 questions'.
Re your other Questions
1. silver mica - that’s fine no problem
2. 0.25W for R16 and R17 - also ok
3. Q10 and Q11. I’ve not tried these in the driver stage, but the best thing is to give it a go. If you pick up any instability, we can circle back and take a look at the compensation.
4. 2SC3264 and 2SA1295 - same comment as the BD139/140 - we may have to look at the comp if you run into instability.
Good luck with your build.
1. silver mica - that’s fine no problem
2. 0.25W for R16 and R17 - also ok
3. Q10 and Q11. I’ve not tried these in the driver stage, but the best thing is to give it a go. If you pick up any instability, we can circle back and take a look at the compensation.
4. 2SC3264 and 2SA1295 - same comment as the BD139/140 - we may have to look at the comp if you run into instability.
Good luck with your build.