VSSA Lateral MosFet Amplifier

PMI · 2013-04-09 2:42 pm

Rick G said:
Use the search this thread function. Search for VSSA BOM.

In other words, you don't know either...

Jokes aside, if you mean the one posted on March 19, I printed it out two weeks ago. That was post 705. I did not come across a definitive list of what is not assembled on the GB circuit board, and not included in the GB, although I suspect there is one somewhere in the intervening 250 posts, therefore my Q.

(feel free to seach for the meaning of the work 'definitive") in your most convenient online dictionary...

)

I like to plan ahead. Just for an example, the Vishay MKT cap is only available from my preferred distributor with a $20 freight charge. While that is not a big a-$$ deal, and I like to avoid unnecessary surprises, like having to stack up spacers, just b/c an exactly 2-mm thick insulator does not happen to be on hand, etc...

Rick G · 2013-04-09 3:07 pm

No offense taken. In that case, you are correct. there is no 'definitive" list as of yet. LC is still working on what he can get preassembled on the boards.

maxlorenz · 2013-04-09 6:18 pm

I think soldering (and desoldering) SMD parts is entertaining and even therapeutic, but ordering the parts for the BOM is very boring and fatiguing...

I wouldn't mind if I have to assemble it all by myself and I wouldn't mind either if "someone" could send me all the parts needed...group buy???

Just an opinion.
M.

PMI · 2013-04-09 6:30 pm

maxlorenz said:
I wouldn't mind if I have to assemble it all by myself and I wouldn't mind either if "someone" could send me all the parts needed...group buy???

Within one area, that might make sense... especially if you have a part that costs $2-3 and has a $20 shipping charge like that Vishay cap with 15-mm spacing...

...3-4 different continents not so much

Either way, if one uses power supplies for around 100 Euro each, this will not be a cheap build!

maxlorenz · 2013-04-10 1:57 am

You're right. It's only laziness from my part.
I can order through RScomponents, pay their high prices and forget about shipping troubles...or through Digikey...
Anyway, I think I'll also build the original VSSA with the parts available in the parts box.

Lazy Cat · 2013-04-10 9:45 am

VSSA GB INFO

Hi guys :wave:

Hope you're doing all right.

As you all probably know VSSA PCB-s are in the production and will be finished probably later next week.

I just want to notice that all SMD material will be preinstalled and the rest of the semiconductors already in the package.

Only 8 parts - capacitors would have to be provided by each GB member individually:

- 10 uF MKT, 2 pcs/PCB
- 1000 uF/50 V, 4 pcs/PCB
- 2200 uF/6,3 V, 2 pcs/PCB

These capacitors should be, as recommendation for the best sound, of top quality available.

I suggest you all to install Vishay-Roederstein and Nichicon, as the best results so far were achieved by these two brands. :yes:

Next info will be about the pricing and addresses. Will be in touch soon.

brianco · 2013-04-10 10:24 am

Thanks LC.

I emailed my details (as requested) a few days ago. I assume that you will invoice by email/PM when all costs are finalised.

maxlorenz · 2013-04-10 11:42 am

Excellent!
Thank you Lazy Cat.

M.

Tyimo · 2013-04-10 11:50 am

After you set up the mentioned bias at first you have to use the two (one each side) trimmer to get read of the offset totally, after full warm up readjust it.

I cann't see any trimmer on the sides in the schematic. Only one in the middle.1K That is for biasing.

PMI · 2013-04-10 1:44 pm

Tyimo said:
I cann't see any trimmer on the sides in the schematic. Only one in the middle.1K That is for biasing.

I think the trimmers are intended to be removed, measured, and replaced with matched surface-mount (?) resistors. There is a pic with surface mount trimmers somewhere here.

AKN · 2013-04-10 2:21 pm

PMI said:
I think the trimmers are intended to be removed, measured, and replaced with matched surface-mount (?) resistors. There is a pic with surface mount trimmers somewhere here.

Hi,

I think the explanation is found here: http://www.diyaudio.com/forums/solid-state/225747-vssa-lateral-mosfet-amplifier-89.html#post3432482

ColinAlex · 2013-04-10 3:18 pm

Capacitor size?

Lazy Cat said:
Hi guys

Only 8 parts - capacitors would have to be provided by each GB member individually:

- 10 uF MKT, 2 pcs/PCB
- 1000 uF/50 V, 4 pcs/PCB
- 2200 uF/6,3 V, 2 pcs/PCB

Hi LC,

What's the lead spacing of the 1000uF/50V? Digikey has them available as 7.5mm and 5.0mm.

Thanks

ColinAlex · 2013-04-10 3:51 pm

Oh dopey me.

Sorry, found the answer. Post 705.

androuski · 2013-04-10 4:13 pm

Whouaou.
It looks terrific. So to make it short can I still be in the GB ?

Telstar · 2013-04-10 4:30 pm

Lazy Cat said:
- 10 uF MKT, 2 pcs/PCB
- 1000 uF/50 V, 4 pcs/PCB
- 2200 uF/6,3 V, 2 pcs/PCB[/B]

These capacitors should be, as recommendation for the best sound, of top quality available.

I suggest you all to install Vishay-Roederstein and Nichicon, as the best results so far were achieved by these two brands.

Please remind us of suggested parts in the BOM

Tyimo · 2013-04-10 5:40 pm

I think the explanation is found here: VSSA Lateral MosFet Amplifier

Thanks!
Unfortunately they are not in the schematic....

Tyimo · 2013-04-10 5:41 pm

How critical are the values of the 22pF and 100pF caps??? Should I use bigger values?

Lazy Cat · 2013-04-10 7:45 pm

VSSA GB material info

androuski said:
Whouaou.
It looks terrific. So to make it short can I still be in the GB ?

Yes, there will be 250 sets in this GB, so at this time there are still some 30 PCB sets available.

Capacitor dimensions for VSSA PCB:

- 10 uF/63 V, MKT, Vishay-Roederstein, 2 pcs
Lead Spacing: 15 mm
External Depth: 8.5 mm
External Height: 17.5 mm
External Width: 18 mm

- 2200 uF/6,3 V, FG, Nichicon, 2 pcs
Lead Spacing: 5 mm
External Diameter: 12,5 mm
External Height: 25 mm

- 1000 uF/50 V, FG, Nichicon, 4 pcs
Lead Spacing: 7,5 mm
External Diameter: 16 mm
External Height: 31,5 mm

Three preinstalled SMD trimmers will be permanently located on PCB, type 5 tourns, Bourns, for DC offset/VAS bias (2) and output bias (1) setting.

I will also add a Kapton insulator for TO-247 and two plastic spacers for TO-126.

Assembling and calibration will be straightforward and very simple. :yes:

Regards Andrej :cheers:

Idefixes · 2013-04-10 7:57 pm

Lazy Cat said:
Yes, there will be 250 sets in this GB, so at this time there are still some 30 PCB sets available.

Capacitor dimensions for VSSA PCB:

- 10 uF/63 V, MKT, Vishay-Roederstein, 2 pcs
Lead Spacing: 15 mm
External Depth: 8.5 mm
External Height: 17.5 mm
External Width: 18 mm

- 2200 uF/6,3 V, FG, Nichicon, 2 pcs
Lead Spacing: 5 mm
External Diameter: 12,5 mm
External Height: 25 mm

- 1000 uF/50 V, FG, Nichicon, 4 pcs
Lead Spacing: 7,5 mm
External Diameter: 16 mm
External Height: 31,5 mm

Three preinstalled SMD trimmers will be permanently located on PCB, type 5 tourns, Bourns, for DC offset/VAS bias (2) and output bias (1) setting.

I will also add a Kapton insulator for TO-247 and two plastic spacers for TO-126.

Assembling and calibration will be straightforward and very simple.

Regards Andrej

Andrej you are :djinn:

Marc

wewe · 2013-04-10 8:56 pm

Dear Lazy Cat if its possible, not to late i will take 1 set for stereo

VSSA Lateral MosFet Amplifier

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