Hi P-A 🙂
Thanks.
Partly because of the design constraints like having a big heatsink and needing to protect the input transformer from external fields...
And as the heart of the amplifier is it's output transformer it seems nice to promote it visually.
The handles are very useful.
I also wanted to keep the overall size small in footprint as each monoblock is meant to live next to the speaker it is driving.
Best wishes,
Susan.
peranders said:Very neat.A tubeless tube amp!
Thanks.
Partly because of the design constraints like having a big heatsink and needing to protect the input transformer from external fields...
And as the heart of the amplifier is it's output transformer it seems nice to promote it visually.
The handles are very useful.
I also wanted to keep the overall size small in footprint as each monoblock is meant to live next to the speaker it is driving.
Best wishes,
Susan.
My neighbor’s boy who is now 16 looked over my shoulder and asked me if I could assemble this beauty for him.
He's playing Bass guitar and thought this would really impress his friends musicians. Such a cool amp behind him on top of his father's old Kustom III Bass.
I told him it was for violins, not for bass 😉
/Hugo
He's playing Bass guitar and thought this would really impress his friends musicians. Such a cool amp behind him on top of his father's old Kustom III Bass.
I told him it was for violins, not for bass 😉
/Hugo
Dear Susan, on all yout measuring I only see results by low or middel levels, which says nothinh abot real listenig quality of amp, mainly if they are made with some " weak " music. Try it make with symphony orchestra and high level, this is real arbiter of quality. Pavel
Hi Hugo,
You might sling together a 2 stage toroid version and see if he likes the sound with his guitar?
For a Bass he doesn't need more than 20 kHz or so bandwidth at the top end as I doubt that the speakers go up that far.
The 15" drivers could be wired in series for 16 ohms, which should work nicely across the swinging inductor of the output toroid for low distortion (that should come from the guitar if desired, not the amp). Those drivers are probably quite sensitive.
The sound could be quite impressive 🙂
Best wishes,
Susan.
Netlist said:
You might sling together a 2 stage toroid version and see if he likes the sound with his guitar?
For a Bass he doesn't need more than 20 kHz or so bandwidth at the top end as I doubt that the speakers go up that far.
The 15" drivers could be wired in series for 16 ohms, which should work nicely across the swinging inductor of the output toroid for low distortion (that should come from the guitar if desired, not the amp). Those drivers are probably quite sensitive.
The sound could be quite impressive 🙂
Best wishes,
Susan.
Hi Pavel,
Low to middle levels i.e. 1 to 12 watts are what I listen to. I can't drive the speakers any louder as I would damage my hearing.
As Mike can attest, 12 or so watts is VERY loud (The Matrix, lobby scene) in my living room.
What one also realizes when listening to this scene is how compressd the film sound really is. I have fired a hand gun (Kimber 45 ACP) and a sub-machine gun (H&K MP5 9mm) at a club (in Dallas) and even with hearing protection they are LOUD.
Also I do my testing in the bedroom/office where I am only running (at the moment) a single amp, usually in bits on the test bench.
Finally I only have a CD source (SACD planned) and playing loud classical music where the average data rate can drop down to 12 bits resolution, isn't really a good test of the amp. ..
... although saying that what one does hear is what is missing.
Hence my preference for recordings that are less dynamic in range as they maintain a higher data resolution.
The amp will drive up to the supply rail quite happily, so max power is max usable power.
Best wishes,
Susan.
Upupa Epops said:
Low to middle levels i.e. 1 to 12 watts are what I listen to. I can't drive the speakers any louder as I would damage my hearing.
As Mike can attest, 12 or so watts is VERY loud (The Matrix, lobby scene) in my living room.
What one also realizes when listening to this scene is how compressd the film sound really is. I have fired a hand gun (Kimber 45 ACP) and a sub-machine gun (H&K MP5 9mm) at a club (in Dallas) and even with hearing protection they are LOUD.
Also I do my testing in the bedroom/office where I am only running (at the moment) a single amp, usually in bits on the test bench.
Finally I only have a CD source (SACD planned) and playing loud classical music where the average data rate can drop down to 12 bits resolution, isn't really a good test of the amp. ..
... although saying that what one does hear is what is missing.
Hence my preference for recordings that are less dynamic in range as they maintain a higher data resolution.
The amp will drive up to the supply rail quite happily, so max power is max usable power.
Best wishes,
Susan.
Well, this would be a good opportunity to finally tackle this amp.Susan-Parker said:
If he collects the money I'll build. 😉
/Hugo
question on transformers
Could Susan or someone explain to me in laymans language why it is that a SMALL toroid tranny is recommended for the i/p gain stage for the initial trial version of the amp. Why not a BIG one
Because my transformer volume control has a voltage gain of 2 a 120V+120V : 25V+25V would be OK in my system.
What is it about a 25VA one that would be better than a 120VA one.
I would have thought that the bigger core would allow less windings - less capacitance - lower resistance.
Could you please explain
many thanks
mike
Could Susan or someone explain to me in laymans language why it is that a SMALL toroid tranny is recommended for the i/p gain stage for the initial trial version of the amp. Why not a BIG one
Because my transformer volume control has a voltage gain of 2 a 120V+120V : 25V+25V would be OK in my system.
What is it about a 25VA one that would be better than a 120VA one.
I would have thought that the bigger core would allow less windings - less capacitance - lower resistance.
Could you please explain
many thanks
mike
Reply
Hi SUSAN-PARKER MIEE,
Could you imagine what will happen to us when we listen to our 1800Wrms amp, i think it wouldl damage our ears, but they are still intact.😀
besides this We have completed our version of your amp and will post the photos soon.
regards,
kanwar
Susan-Parker said:
Hi SUSAN-PARKER MIEE,
Could you imagine what will happen to us when we listen to our 1800Wrms amp, i think it wouldl damage our ears, but they are still intact.😀
besides this We have completed our version of your amp and will post the photos soon.
regards,
kanwar
Re: question on transformers
Hi Mike,
Well, a smaller transformer is less expensive and would of course be easier to drive... being smaller... wouldn't it???
The 15 VA toroid did run up a little higher than the 30 VA but as the later was 20 years or older and a different spec not easy to really tell as the difference was small.
A quick test using a OP275 dual opamp balanced drive, and a 120K Rterm across the 230 output (plus a scope probe):
Test was maximum frequency for a given output voltage before distortion was visibly apparent or the output had dropped by -3dB.
15VA toroid 115+115 : 2 x 12
=============================
Drive across both 12 volt windings - i.e. 24:230 step up.
111 mH across both windings, 230 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 27 kHz
7 Vac (20 Vpp) 20 Hz to 25 kHz
12 Vac (35 Vpp) 20 Hz to 10 kHz
22 Vac (60 Vpp) 20 Hz to 5 kHz
217 VA toroid 115+115 : 2 x 31 @ 3.5A
=====================================
Drive to one 31 volt winding - i.e. 31:230 step up.
98 mH per 31 V winding, 727 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 65 kHz
5 Vac (16 Vpp) 20 Hz to 50 kHz
14 Vac (40 Vpp) 20 Hz to 17 kHz
28 Vac (80 Vpp) 20 Hz to 8 kHz
56 Vac (160 Vpp) 20 Hz to 2 kHz
Um, interesting.
I am not sure how well the transformer volume control will do though.
Best wishes,
Susan.
Hi Mike,
mikelm said:
Well, a smaller transformer is less expensive and would of course be easier to drive... being smaller... wouldn't it???
The 15 VA toroid did run up a little higher than the 30 VA but as the later was 20 years or older and a different spec not easy to really tell as the difference was small.
A quick test using a OP275 dual opamp balanced drive, and a 120K Rterm across the 230 output (plus a scope probe):
Test was maximum frequency for a given output voltage before distortion was visibly apparent or the output had dropped by -3dB.
15VA toroid 115+115 : 2 x 12
=============================
Drive across both 12 volt windings - i.e. 24:230 step up.
111 mH across both windings, 230 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 27 kHz
7 Vac (20 Vpp) 20 Hz to 25 kHz
12 Vac (35 Vpp) 20 Hz to 10 kHz
22 Vac (60 Vpp) 20 Hz to 5 kHz
217 VA toroid 115+115 : 2 x 31 @ 3.5A
=====================================
Drive to one 31 volt winding - i.e. 31:230 step up.
98 mH per 31 V winding, 727 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 65 kHz
5 Vac (16 Vpp) 20 Hz to 50 kHz
14 Vac (40 Vpp) 20 Hz to 17 kHz
28 Vac (80 Vpp) 20 Hz to 8 kHz
56 Vac (160 Vpp) 20 Hz to 2 kHz
Um, interesting.
I am not sure how well the transformer volume control will do though.
Best wishes,
Susan.
Re: Reply
Hi Kanwar,
Probably not in a room of 3.5 by 4 meters in size though?
Look forward to seeing the pics 🙂
Best wishes,
Susan.
Hi Kanwar,
Workhorse said:
Probably not in a room of 3.5 by 4 meters in size though?
Look forward to seeing the pics 🙂
Best wishes,
Susan.
Re: Re: question on transformers
Hi Susan many thanks for your reply and research
Well, a smaller transformer is less expensive and would of course be easier to drive... being smaller... wouldn't it???
well I thought that the reflected impedance would be predominant at audio frequencies and cost wise I thought that with a gain of 5 a bigger toroid might be very good and good value compaired with the sowter. I am not sure where core losses come into play.
A quick test using a OP275 dual opamp balanced drive, and a 120K Rterm across the 230 output (plus a scope probe):
Test was maximum frequency for a given output voltage before distortion was visibly apparent or the output had dropped by -3dB.
15VA toroid 115+115 : 2 x 12
=============================
Drive across both 12 volt windings - i.e. 24:230 step up.
111 mH across both windings, 230 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 27 kHz
7 Vac (20 Vpp) 20 Hz to 25 kHz
12 Vac (35 Vpp) 20 Hz to 10 kHz
22 Vac (60 Vpp) 20 Hz to 5 kHz
217 VA toroid 115+115 : 2 x 31 @ 3.5A
=====================================
Drive to one 31 volt winding - i.e. 31:230 step up.
98 mH per 31 V winding, 727 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 65 kHz
5 Vac (16 Vpp) 20 Hz to 50 kHz
14 Vac (40 Vpp) 20 Hz to 17 kHz
28 Vac (80 Vpp) 20 Hz to 8 kHz
56 Vac (160 Vpp) 20 Hz to 2 kHz
Um, interesting.
yes - so the response drops off with volume
I am not sure how well the transformer volume control will do though.
yes - I may have to buffer it - I will experiment.
I will order my sowters in the next few days
best wishes
mike
Hi Susan many thanks for your reply and research
Well, a smaller transformer is less expensive and would of course be easier to drive... being smaller... wouldn't it???
well I thought that the reflected impedance would be predominant at audio frequencies and cost wise I thought that with a gain of 5 a bigger toroid might be very good and good value compaired with the sowter. I am not sure where core losses come into play.
A quick test using a OP275 dual opamp balanced drive, and a 120K Rterm across the 230 output (plus a scope probe):
Test was maximum frequency for a given output voltage before distortion was visibly apparent or the output had dropped by -3dB.
15VA toroid 115+115 : 2 x 12
=============================
Drive across both 12 volt windings - i.e. 24:230 step up.
111 mH across both windings, 230 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 27 kHz
7 Vac (20 Vpp) 20 Hz to 25 kHz
12 Vac (35 Vpp) 20 Hz to 10 kHz
22 Vac (60 Vpp) 20 Hz to 5 kHz
217 VA toroid 115+115 : 2 x 31 @ 3.5A
=====================================
Drive to one 31 volt winding - i.e. 31:230 step up.
98 mH per 31 V winding, 727 pF Pri to Sec.
4 Vac (11.7 Vpp) 20 Hz to 65 kHz
5 Vac (16 Vpp) 20 Hz to 50 kHz
14 Vac (40 Vpp) 20 Hz to 17 kHz
28 Vac (80 Vpp) 20 Hz to 8 kHz
56 Vac (160 Vpp) 20 Hz to 2 kHz
Um, interesting.
yes - so the response drops off with volume
I am not sure how well the transformer volume control will do though.
yes - I may have to buffer it - I will experiment.
I will order my sowters in the next few days
best wishes
mike
Site Down Again
Susan,
Went to your site http://www.susan-parker.co.uk over the last 3 days and its been down. Have you changed your domain or are there server problems?
Susan,
Went to your site http://www.susan-parker.co.uk over the last 3 days and its been down. Have you changed your domain or are there server problems?
Website Access
Hi,
Thanks for your posts.
I hope everyone is keeping well.
I am not aware of any problems my end... but it's always posible that a router went down somewhere and lost my address?
Conversly I had problems accessing the DIYforum last week.
Hopefully everything is now working okay.
Can always email me direct if there is a problem 🙂
Best wishes,
Susan.
Hi,
Thanks for your posts.
I hope everyone is keeping well.
I am not aware of any problems my end... but it's always posible that a router went down somewhere and lost my address?
Conversly I had problems accessing the DIYforum last week.
Hopefully everything is now working okay.
Can always email me direct if there is a problem 🙂
Best wishes,
Susan.
Hi all,
Well I've finally started work on my first experimental prototype using toriods for now.
after I've tried various different options I'm planning to build an all singing, all dancing, no holds barred, as high end as possible, version.
thanks of your help & inspiration Susan
I'll post my progress
mike
Well I've finally started work on my first experimental prototype using toriods for now.
after I've tried various different options I'm planning to build an all singing, all dancing, no holds barred, as high end as possible, version.
thanks of your help & inspiration Susan
I'll post my progress
mike
Hi Mike,
Good to hear, looking forward to the updates 🙂
Which size toroids did you go for?
Best wishes,
Susan.
mikelm said:
Good to hear, looking forward to the updates 🙂
Which size toroids did you go for?
Best wishes,
Susan.
Susan-Parker said:
i/p transformers 25VA & 120VA - both 25V + 25V
o/p chokes 160VA 12V + 12V & 225VA 18V + 18V.
( mind you the Antrim 160VA has the same sized core as the 225VA ! )
both have enough inductance for my high current implementation - 20mH per coil.
my first prototype will run at 12V and 2 x 4A which means I can try SLA batteries as well
In simulation this gives round about 0.07% 3rd HD at 10V peak into 8 ohms ( which is where I usually measure it in simulation )
mike
Hi Mike,
Will be interesting to see the bandwidth difference between the two.
Um. Possibly the 18+18 but you say they have the same inductance.
Will you be using some of those "developed for automotive" low voltage mosfets?
Look forward to the comparison between simulation and reality.
Best wishes,
Susan.
mikelm said:
Will be interesting to see the bandwidth difference between the two.
Um. Possibly the 18+18 but you say they have the same inductance.
Will you be using some of those "developed for automotive" low voltage mosfets?
Look forward to the comparison between simulation and reality.
Best wishes,
Susan.