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VSSA Lateral MosFet Amplifier

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W

woofertester

Member
Joined 2011
I am very happy to be on the list. Looking forward to using these. Please let me know where to send the funds, etc.

Thank you LC for your efforts.

Lazy Cat said:
BYRTT 8 PCB set
CaféNoir 6 PCB set
ColinAlex 8 PCB set
DavorXXL 6 PCB set
DuffyDawg 4 PCB set + 4 SMPS400
electromf 4 PCB set
badrisuper 2 PCB set
volavola 2 PCB set
JethroTull 2 PCB set
kp93300 2 PCB set
momomo67890 4 pcb set
ua3grn 6pcb set
mj777 2pcb set
mkusan 2pcb set
Odysseas 4pcb (2 pairs)
hcbonfim 2pcb set
Albrerta 2pcb set
dw1narso 2 pcb set (1 stereo)
supernet 2 pcb set
milandks 4pcb set
tjencks 2pcb set
quanghao: 2pcb set
audionootje: 4pcb set (2x stereo)
tritosine 4pcb (2 pairs)
Bobo le Chat 2 pcb set
AP2 2pcb set+2pcb empity (i need this also)
Meganinja 2 set ( stereo )
mikvous 2 pcb set
Rick G 2 PCB set
kindhornman 2 boards
ravid 2 pcb set 100
gnat 2 pcb set
potepuh 2 pcb set
metallicus69 4 pcb set
Ranchu32 2 pcb set
woofertester 4 pcb set
__________________________________________________________
114 VSSA PCB set


Optional GB list if any from above will cancel the order:

siberia 1 pcb (if possible) - not possible, please send broken VSSA to repair ;)
edbk 4 pcb set
Raj1 2 pcb set (or 6 if available)
analog_sa 2pcb set (will even take 1 if none are left)
mravlca 2pcb set
Cuda 2pcb set


Guys please check GB list and if any from above the line list would like to cancel the order please say it now, so the guys from optional GB list can be supplied. :)

Regards L.C. :cheers:
Click to expand...
 
BYRTT

BYRTT

Member
Joined 2009
Qoute: 2282.
Here is attached files for circuit schematic v1.3 and v1.4 to use in TINA TI v9.xx.
Program is free get it at Texas Instruments website.
IMPORTANT: The exentension (*.txt) should be renamed to (*.tsc), else i could not attach because of extension limit at this site.
Ricky
 

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D

dw1narso

Member
Joined 2004
@LazyCat: I'm about to order the capacitors for your board. Would there be any benefit if I increase the capacitance of the 1000uF and 2200uF Caps, provided that I could find the capacitor with the same space/lead size?

In my case, getting Nichicon FG is very non-economical (for example Mouser charge $30 just for the shipping cost) and I'm considering to use Panasonic FM instead from Farnell.

-David
 
Lazy Cat

Lazy Cat

Member
Joined 2007
VSSA PCB set - 2nd GB Final List

GB Final List:

BYRTT 8 PCB set (already payed - payment received)
CaféNoir 6 PCB set (already payed - payment received)
ColinAlex 8 PCB set (already payed - payment received)
DavorXXL 6 PCB set
DuffyDawg 4 PCB set + 4 SMPS400 (already payed - payment received)
electromf 4 PCB set (already payed - payment received)
badrisuper 2 PCB set
volavola 2 PCB set
JethroTull 2 PCB set
kp93300 2 PCB set
momomo67890 4 pcb set
ua3grn 6pcb set
mj777 2pcb set
mkusan 2pcb set
Odysseas 4pcb (2 pairs)
hcbonfim 2pcb set
Albrerta 2pcb set
dw1narso 2 pcb set (1 stereo)
supernet 2 pcb set
milandks 4pcb set
tjencks 2pcb set
quanghao: 2pcb set
audionootje: 4pcb set (2x stereo)
tritosine 4pcb (2 pairs)
Bobo le Chat 2 pcb set
AP2 2pcb set+2pcb empity (i need this also)
Meganinja 2 set ( stereo )
mikvous 2 pcb set
Rick G 2 PCB set
kindhornman 2 boards
ravid 2 pcb set
gnat 2 pcb set
potepuh 2 pcb set
metallicus69 4 pcb set
Ranchu32 2 pcb set
woofertester 4 pcb set
______________________________________________
114 VSSA PCB set


Hi GB members. :wave:

Now is the time to send your exact address information to:

esl@siol.net


Please prepare your address information in most exact form, like this:

1. line: Your diyAudio Forum Name (very very important)
2. line: Company Name (if not any please skip this line)
3. line: First Name Second Name (family name)
4. line: Street Name Street Number
5. line: Street or District Name (if not any please skip this line)
6. line: City Code Number (postal number) City Name
7. line: Province or State Name (if not any please skip this line)
8. line: Country Name
9. line: e-mail address (very very important)

I will prepare the Proforma Invoices for all of you and send them to your e-mail addresses. There will be all informations necessary to confirm and pay your orders. :yes:

Please do not send any info to diyAudio PM, only to esl@siol.net. Thanks. :)

If I will not receive the info from some GB member, I will imediately inform the first one from the Optional GB list to step in instead. :yes:

Regards to all L.C. :cheers:
 
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Lazy Cat

Lazy Cat

Member
Joined 2007
Esperado said:
To LC and others, may-be this can interest-you:

http://www.esperado.fr/temp/VSSA/cfa-vs-vfa.html

Distortion, bandwidth, slewrate, noise, PSRR etc.
Click to expand...

Esperado, you are a great friend, happy to have you around here, my admiration to you. :hug:
This is a great contribution to this thread which will help many of us to understand the topic even deeply by your step by step presentation. Many thanks for your will and time spent. :worship:
 
BYRTT

BYRTT

Member
Joined 2009
Esperado said:
To LC and others, may-be this can interest-you:

http://www.esperado.fr/temp/VSSA/cfa-vs-vfa.html

Distortion, bandwidth, slewrate, noise, PSRR etc.
Click to expand...

Lazy Cat said:
Esperado, you are a great friend, happy to have you around here, my admiration to you. :hug:
This is a great contribution to this thread which will help many of us to understand the topic even deeply by your step by step presentation. Many thanks for your will and time spent. :worship:
Click to expand...
Hi Christophe and Andrej i have run simulation with Christophes circuit schematics for CFB and VFB which i attach as images (Thanks for the link Christophe).
When i remove "C4" from the VFB version it outperforms the other two except distortion.
Bear over with me i am hobbyist so only few of your knowlegde, but will the setup without "C4" be possible to realworld ?.
The models used for VAS and Output devices are not real manufacturer models but generic types from TINA program, but precision should not matter because the three simulations are compareable.
So Andrej should we buy a pair of BC550/560 and few resistors for tuneup ?
Regards Ricky
 

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Esperado

Esperado

Banned
Joined 2011
esperado.fr
BYRTT said:
When i remove "C4" from the VFB version it outperforms the other two except distortion.
will the setup without "C4" be possible to real world ?.
Click to expand...
Hum...Did-you measured slew rate ? I doubt there will be a big change and that's the important point. I mean, that makes all the difference in listening experience, witch make some prefer current feedback amplifiers.(on my point of view)
We are not fighting about bandwidth witch is anyway killed by the input low pass filter. ;-).
By the way, this comparison is on an educational point of view, to make discover some things about current feedback, and kill some urban legend about more noise and distortion, as an example.

Without the cap, i doubt you can have a decent DC offset. And the cap is fair in this comparison, as it correspond to the C4 C6 of the VSSA (same response curve in low frequency).

I have to apologize, i made a little error with the input stage current: i did not took in consideration the currents used by the feedback path in CFA. I had spend some more hours to tune the VFA to perfectly match the CFA, both in gain and current in transistors of all stages. Guess what ?
The distortion of the VFA worsen. 0.001059 at 1000Hz. (it was 0.000978)
Oh Lord, don't buy me two extra transistors :)
 
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K

kgrlee

Member
Joined 2011
FETs for input current sources

Can someone point me to SPICE models for the FETs used in the input current sources. I think they are 2n5462.

I saw LC had a procedure to adjust these too but I've lost it.

Please excuse me but I'm slowly reading through the thread but am only at about #100
 
Salas

Salas

diyAudio Chief Moderator
Joined 2002
Paid Member
*PHILIPS SEMICONDUCTORS Version: 1.0
*Filename: BF245B.PRM Date: Oct 1992
*
.MODEL BF245B NJF
+ VTO = -2.3085E+000
+ BETA = 1.09045E-003
+ LAMBDA = 2.31754E-002
+ RD = 7.77648E+000
+ RS = 7.77648E+000
+ IS = 2.59121E-016
+ CGS = 2.00000E-012
+ CGD = 2.20000E-012
+ PB = 9.91494E-001
+ FC = 5.00000E-001
*Parameter with default value: FC
 
K

kgrlee

Member
Joined 2011
analog_sa said:
BF545B

Why on earth would you need spice models? They are clearly set to 2.4mA...
Click to expand...
Salas says bf245. Both of these are 30V Vds max so would be iffy for a 50W 8R version.

2n5462 is 40V Vds max so probably OK for 50W 8R.

Anyone know where the adjustment procedure is? It looks like you'd have to tweak both sides for IPS current as well as DC offset.
________________

Salas, where do you get these Philips SPICE models?
 
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