I have a transformer from an old radio, which had a better sound than most at the time. I have it on my bench with a pair of 1W MOSFETs, VN10 series. I was about to try a circuit like the old germanium ones but using MOSFETs, when Susan posted her design. I had even bought a Visaton FRS 8 speaker to try with the old circuit. I have a 20W transformer kit that i've used, but I could rewind it. Not sure about the quality of laminations though. The input transformer is the problem.
It will not be a fair comparison to use crappy transformers in her circuit, so sound quality issues will have to wait until someone has worthy transformers to build it with. It would still be fun to try it though.
It will not be a fair comparison to use crappy transformers in her circuit, so sound quality issues will have to wait until someone has worthy transformers to build it with. It would still be fun to try it though.
Vbias circuit
Hello Susan!
Congratulate for your new and "mind refreshment" design!
At the same time I would like to please you to post here a whole, detailed schematic with the bias circuit and PSU, if it is possible. I am affraid that I didn't understand the "Vbias" 100%. I am an amateur...
Thanks and best regards:
Tyimo
Hello Susan!
Congratulate for your new and "mind refreshment" design!
At the same time I would like to please you to post here a whole, detailed schematic with the bias circuit and PSU, if it is possible. I am affraid that I didn't understand the "Vbias" 100%. I am an amateur...
Thanks and best regards:
Tyimo
Wellll...
Lots of interest from all of you.
So now it is up to Susan?? You must be kidding!
Susan gave you a design, she arranged for a company to provide the output transformer kits, she gave you the type number of the input transformer at Sowter, and all you do is look at each other and wait for, for what? Place your orders!
Jan Didden
Lots of interest from all of you.
So now it is up to Susan?? You must be kidding!
Susan gave you a design, she arranged for a company to provide the output transformer kits, she gave you the type number of the input transformer at Sowter, and all you do is look at each other and wait for, for what? Place your orders!
Jan Didden
I tried a 800VA tranny in the output section of my Circlotron-amp yesterday,it is not the same thing, but it worked very good.
My little 14 watt solidstate circlo made my girlfriend quite angry driving 2 10 inch CervinVega carwoofers with Infected Mushroms.The load whas 1.5 to 2 ohms.
it was only an experment with trannies.
My little 14 watt solidstate circlo made my girlfriend quite angry driving 2 10 inch CervinVega carwoofers with Infected Mushroms.The load whas 1.5 to 2 ohms.
it was only an experment with trannies.
Hi,
In response to Grahams post about the transformer characteristics I ran a test using the 75 watt transformer with 50 ohm source and 50 ohm load to see what was happening at the top end.
Khz Volts
100 0.7764
200 0.7945
300 0.6768
400 0.2030
500 0.3426
600 0.5228
700 0.5670
800 0.5728
900 0.5531
1000 0.5218
2000 0.5607
3000 0.3793
4000 0.7646
5000 0.8036
6000 0.7004
7000 0.7334
8000 0.6724
9000 0.4179
10000 0.4506
12000 0.7174
15000 0.5910
20000 0.6655
25000 0.3724
30000 0.2701
40000 0.2545
50000 0.3798
60000 0.2264
70000 0.1698
80000 0.2877
90000 0.3855
100000 0.2553
110000 0.1134
120000 0.2350
130000 0.1581
140000 0.1428
150000 0.1013
160000 0.0641
170000 0.1433
180000 0.0611
190000 0.0682
200000 0.0887
300000 0.0647
400000 0.0490
500000 0.0321
600000 0.0466
700000 0.0062
800000 0.0140
900000 0.0374
1000000 0.0045
Notes:
As the setup isn't properly designed for the higher frequencies there are some bumps.
Yes, I can measure to 4 decimal places.
Yes, final measurment is 1 GHz.
Best wishes,
Susan.
(will reply to the various posts tomorrow)
In response to Grahams post about the transformer characteristics I ran a test using the 75 watt transformer with 50 ohm source and 50 ohm load to see what was happening at the top end.
Khz Volts
100 0.7764
200 0.7945
300 0.6768
400 0.2030
500 0.3426
600 0.5228
700 0.5670
800 0.5728
900 0.5531
1000 0.5218
2000 0.5607
3000 0.3793
4000 0.7646
5000 0.8036
6000 0.7004
7000 0.7334
8000 0.6724
9000 0.4179
10000 0.4506
12000 0.7174
15000 0.5910
20000 0.6655
25000 0.3724
30000 0.2701
40000 0.2545
50000 0.3798
60000 0.2264
70000 0.1698
80000 0.2877
90000 0.3855
100000 0.2553
110000 0.1134
120000 0.2350
130000 0.1581
140000 0.1428
150000 0.1013
160000 0.0641
170000 0.1433
180000 0.0611
190000 0.0682
200000 0.0887
300000 0.0647
400000 0.0490
500000 0.0321
600000 0.0466
700000 0.0062
800000 0.0140
900000 0.0374
1000000 0.0045
Notes:
As the setup isn't properly designed for the higher frequencies there are some bumps.
Yes, I can measure to 4 decimal places.
Yes, final measurment is 1 GHz.
Best wishes,
Susan.
(will reply to the various posts tomorrow)
Upupa Epops said:Realy high fidelity, Susan.
i might be totally ignorant here, so correct me if i'm wrong. but statistics is the science (or art, really) of making the data say what you want. aren't we generally used to seeing graphs such as this in db (probably because they *look* better)? and then isn't 3db twice (or half) the voltage? again...i might be off a bit on specific details...but hopefully what i'm trying to convey gets through. and basically...it is that this graph seems more drastic since it is provided in volts? aside from the dip at 400hz...wouldn't the 100hz to 20khz performance then be *within* 3db (ie: +- 1.5db) since the range is from about .4 to .8 (ie: a doubling of voltage). if that is correct...then the whole thing can even be within +- 3db, or even less (including the dip at 400hz).
again...my figures might be off...so correct me if i'm wrong. i just thought this when looking at it (and remember statistc courses in college).