(AK) Class A HA PCB and parts Group Buy

[Deleted]

Apr 19, 2013 19:05:06 GMT asdiasx said:

Thanks Will, good to know all this...
If I have some time, I'll try to do a prototype with local parts only to have a small taste... 

Rgd

Cool

let us know how you get on.

take care

[pingu]

Apr 19, 2013 19:05:06 GMT asdiasx said:

Thanks Will, good to know all this...
If I have some time, I'll try to do a prototype with local parts only to have a small taste... 

Rgd

Hi asdiax,

Nice to have you join us, they are all very helpful on here (and I need it too ).
If you have real problems with parts I have a local Radio Spares so can pop into the trade counter and collect any bits and post them on to you if the parts are small. That way there is no minimum order, if that is any help.


Shaun and all the others who were invaluable to getting this sorted,

PSU's up and running and the JLH RE's seem OK with them. Small accident when I miss connected one and had a cap pop on me. A "stray" cat was visiting at the time she left very quickly tho and took nearly an hour to venture cautiously back.
My thanks to everyone who helped me to get them working.
Next step the Brice HA while I wait for the GB
Once again Thanks to everyone who helped

[Deleted]

Apr 28, 2013 22:40:18 GMT pingu said:

Apr 19, 2013 19:05:06 GMT asdiasx said:

Thanks Will, good to know all this...
If I have some time, I'll try to do a prototype with local parts only to have a small taste... 

Rgd

Hi asdiax,

Nice to have you join us, they are all very helpful on here (and I need it too ).
If you have real problems with parts I have a local Radio Spares so can pop into the trade counter and collect any bits and post them on to you if the parts are small. That way there is no minimum order, if that is any help.


Shaun and all the others who were invaluable to getting this sorted,

PSU's up and running and the JLH RE's seem OK with them. Small accident when I miss connected one and had a cap pop on me. A "stray" cat was visiting at the time she left very quickly tho and took nearly an hour to venture cautiously back.
My thanks to everyone who helped me to get them working.
Next step the Brice HA while I wait for the GB
Once again Thanks to everyone who helped

Good work Martin

popping caps oh yes we've all had at least one of those.

but that's a quick way to learn to double check before power up .

well done

take care

[pingu]

Hi Shaun,
Well I thought I had double checked everything, and the cat who sits on the end of the bench when she visits DEFINITELY check all the bits out. Obviously we were both mistaken.
Martin

[asdiasx]

Apr 28, 2013 22:40:18 GMT pingu said:

Hi asdiax,

Nice to have you join us, they are all very helpful on here (and I need it too ).
If you have real problems with parts I have a local Radio Spares so can pop into the trade counter and collect any bits and post them on to you if the parts are small. That way there is no minimum order, if that is any help.

THANK YOU Pingu!!! I really appreciate your offer... I've just stared to collect parts and got the output transistors from "Mercadolivre" a kind of local "ebay" .

This first version will begin with discrete transistors and diode at the input stage...

Lets see if I can get everything, if I miss something I"ll let you and friends here know!

Regards,

Adriano

[gommer]

Hi guys, it's been a while, sorry about that.

I'll start with an updated participants list, please comment on it if something's not right. I'll next be working on the BOM and kit price, keeping all suggestions into account.


/edited: removed list, please edit the google docs spreadsheet from now on.

[Deleted]

Hi Marc,

Thanks for picking this up again. Can you remove me from the "LS352 & LS313" list, I still have a full spare set.

Cheers.

[gommer]

Jun 1, 2013 17:57:11 GMT @cjarchez said:

Can you remove me from the "LS352 & LS313" list, I still have a full spare set.

Done.

[Deleted]

Hi Marc

Can you put me down for 4 x PSU boards please?

Thanks in advance

Take care

[gommer]

Jun 1, 2013 22:06:44 GMT @shaun said:

Can you put me down for 4 x PSU boards please?

Done

[Deleted]

Thanks very much Marc

[pingu]

Hi Marc,
Can you put me down for
HA/Pre Boards x4
LS352 & LS313 x4
PS PCB x6
Parts x2
My neighbour may have droped out but I'll take a set of HA/pre, PSU boards and a LS352 & LS313 set for him and if he is out use them as a mule.
Thanks
Martin

[gommer]

Jun 2, 2013 12:49:06 GMT pingu said:

Can you put me down for...

Done

[gommer]

/edit:
removed BOM and price info. Please visit the google docs spreadsheet for real time price info.

[Deleted]

Hi Marc
That BOM is of course for just 1 Channel, but what is this "SK129 x2 " ?
Kind Regards
Alex

[gommer]

Jun 3, 2013 7:43:43 GMT @sandyk said:

Hi Marc
That BOM is of course for just 1 Channel, but what is this "SK129 x2 " ?
Kind Regards
Alex

Hi Alex,

Yes, this BOM is for one PCB, hence one channel. Also without PSU, that will follow.
The SK129 part is a TO220 heatsink (Fischer elektronik).

Cheers, Marc

[Deleted]

Hi Marc
Thanks for the clarification.
In case any are wondering why the removal of "S.C." from the title of the 2 threads, it is because Silicon Chip magazine did not publish a discrete Class A HA/Preamp design as alluded to elsewhere.
Kind Regards
Alex

[Deleted]

Hi Marc

Sorry to be a nuisance but, so long as it doesn't affect the GB for others, could you drop me out please?

I've decided to destock my cupboards so no sense in storing up another project I'll not get around to making.

If it causes you or the GB any problems don't worry, I'll honour my commitment.

Regards

Syd

[gommer]

Hi Syd,

I'll see what the impact is this evening. I don't see problems for the PCB, but it might be significant for parts.
OTOH, if more people want matched transistor pairs/quads/sets, then that could also impact price a lot for the better.

Marc

[pingu]

For all transistors, this price is based on buying 100 per type and dividing this total cost amongst the total needed numbers. This allows for matching, but it leaves a lot of waste. I haven't decided yet how it could be managed in a more fair way and it could end up being cheaper if I find a way.

Read more: rockgrotto.proboards.com/thread/8894/class-pcb-parts-group-buy?page=9#ixzz2V99u5oUU

Hi Marc,
Have you looked at Mouser Electronics they do good discount for bulk buys of 100 or so transistors.
Martin

[gommer]

Jun 3, 2013 10:16:39 GMT pingu said:

For all transistors, this price is based on buying 100 per type and dividing this total cost amongst the total needed numbers. This allows for matching, but it leaves a lot of waste. I haven't decided yet how it could be managed in a more fair way and it could end up being cheaper if I find a way.

Read more: rockgrotto.proboards.com/thread/8894/class-pcb-parts-group-buy?page=9#ixzz2V99u5oUU

Hi Marc,
Have you looked at Mouser Electronics they do good discount for bulk buys of 100 or so transistors.
Martin

Hi Martin, these prices ARE based on Mouser prices. Indeed the volume discounts are significant. That's also why I choose 100 and not e.g. 50.

I've checked RS, Farnell, Digi-key and Mouser and Mouser is by far the cheapest for volume pricing, for most parts, not all. I've limited the suppliers to Mouser and Farnell, some parts are not available on Mouser (e.g. the Fischer heatsinks).

To give an example of the price influence based on the number of participants. Many of the small signal transistors are only a few cent per 100.
100 x €0.05 = €5. 5 participants, 10 parts needed makes €0.5 per piece. 10 participants, 20 parts needed makes €0.25 per piece. Relatively, that's a big difference and it adds up quickly.

Marc

[pingu]

Hi Marc,
Have you looked at Mouser Electronics they do good discount for bulk buys of 100 or so transistors.
Martin[/quote]


I've just done a quick search on Mouser and 100 of each of the BC transistor (700 in all) comes to about 56.00 Euro.
I have an account with them and if it helps I can order them for you with no carriage charge and forward them to you.
I bought a load of 2SA1930 and 2SC5171 for the JLH ripple eater and found them to be very close indeed just as they cane so should be no worries about thier matching,
All The Best
Martin

[pingu]

Sorry Marc,
Dissregard the last post I see what you mean.
Wasn't questioning your maths just trying to be helpful. BTW if you want the free postage option just shout, but maybe on your order it will qualify for free postage anyway
Regards Martin

[gommer]

Thanks for the offer Martin, but I can also order without shipping costs, at my own account through work. Prices are as indicated on the site, but no minimum order, nor
shipping charges. I have all the parameters in an excel, I'll check this evening. But if you come to the amount mentioned for the BC devices, then my excell should reflect the same.

When you say that the 2SA and 2SC devices match, do you mean the spread within one type or a match between NPN and PNP types?

[pingu]

Both Marc, only matched on a DMM but easey get matchs within 10%... maybe I was just lucky tho.
I also have a local RS so can collect if it helps
Martin