(AK) Class A HA PCB and parts Group Buy

[gommer]

Hello again,

@syd, I've removed you from the list. It doesn't affect total price too much, so i think it'll be OK.

Total price for buying 100 pieces (or 50 where appropriate) of all semiconductors (including the 3V3 zener and SF12, 2 versions of BC327 and BC337: -25 and -40) and then dividing the cost amongst all currently interested, results in a total of €12.77 per channel or €25.54 total per amp. That's reasonable for dividing the cost amongst only 6 amps. If more people are interested in matched sets, then the price goes down.

The BOM price per HA PCB (excluding resistors and PCB) is now at €36,5 or €73 per amp. I'll need to check for the PCB price, which I can as size is final.

I'll keep this open a bit longer. I can't order the PCB yet anyway, as there's a small error in the layout/schematic that Will has sent me. Meanwhile, I'll have a look at the PSU PCB and parts.

Cheers, Marc

[jeffc]

Hi Marc,
I'll take Syds 2 x boards in the GB if that's OK.

Being my luck I'll stuff up the 3 mm thick PCBs attending to mods to my Class A HA and these could come in very handy. Or I have most parts to build a dedicated Pre should I ever get bored in retirement....

cheers.. jeffc

PS. Just to qualify, sorry, I'd only need the PCBs... and maybe the dual transistors in the way of components.

[Deleted]

Is this any help Marc?
I don't know if you are offering only full kit sets or cherry picking too but this should hopefully give both options?

It should, in theory, a case of copying the table and adding your info.(First time doing a proboards table so not sure)

PART REF	VALUE	DEVICE	Quantity per  stereo pair		asdiasx	gommer	pingu	spirit
C1	100PF	polystyrene	2
C2	68PF	polystyrene	2
C3,4,6,10,18,19,20	100nf	MKT	14
C5,7,8,9,11,21,22	100uf	lytic	14
C16	1uf	MKT	2
C17	3u3	MKT	2
D1	SF12	Diode	2
D2	c3v3	Zener diode	2
T1	BC559	TO92	2
T2	LS352	Dual	2
T3	LS313	Dual	2
T4	BC558B	TO92	2
T5	BC557B	TO92	2
T6 & T8	BC547	TO92	4
T7	BC549C	TO92	2
T9	BC337	TO92	2
T10	BC327	TO92	2
T11	2SA1930	TO220	2
T12	2SC5171	TO220	2
VR1	78L15	TO92	2
VR2	79L15	TO92	2
IC1	OPA134	DIP8	2
CONNECTORS	vertical 2 way	5mm pitch	10
HEATSINKS	twin fin	25.5mm pitch	4
TRIMMER	500r	bournes	4

[Deleted]

Jun 3, 2013 17:07:50 GMT gommer said:

I've removed you from the list. It doesn't affect total price too much, so i think it'll be OK.Cheers, Marc

Thanks Marc, sorry for the hassle, I meant what I said, if it messes up your discounts I'll pay my share. So when you're finalising just PM me.

Syd

[gommer]

Alright, I've decided what to do. Thanks Chris for your courageous effort, but editing these forum tables will be a nightmare and it would remain impossible to simple copy paste from a spreadsheet.

So, I'll be tidying up my spreadsheet and use Chris's idea to format it and drop that on Google docs. You'll be able to edit the requested numbers yourselves and see the price change in real time.

It'll be a lot easier to cherry pick individual items this way, you're all welcome to do so. I'll post as soon as it's finished and online.

Cheers, Marc

[gommer]

Here you go, order at will in this spreadsheet
But PLEASE, only edit order numbers for yourselves in the 'Orders' tab.

You'll find that the spreadsheet auto updates price per part and totals per participant. In the 'BOM' sheet you'll find the BOM (duh) with links to the exact items that i intend to buy.

As indicated above, you're welcome to select individual items. If you intend to order complete sets, then select the set, for your convenience. You can additionally order extra items on top of the set if you want.

All items bought in bulk (typically 100 or 50) will be matched in pairs or quads, as appropriate.

Cheers, Marc

[Deleted]

thanks Marc

[gommer]

You're welcome.

BTW, price of PCB's is at zero for the moment, but they're not free

[gommer]

Jun 3, 2013 20:38:26 GMT jeffc said:

Hi Marc,
I'll take Syds 2 x boards in the GB if that's OK.

Hi Jeff,

You're welcome to add yourself to the spreadsheet now. Just add your name in the first tab and fill in the numbers. You're my Guinea pig

Cheers, Marc

[asdiasx]

Hi everybody! I'm in!

Shaun, thanks for the reminder!

Rgds

[gommer]

Update: HA PCB price has been added (also roughly adapting to ordered numbers).

[Deleted]

Very slick work Marc.

[Spirit]

Jun 5, 2013 22:28:17 GMT @shaun said:

Very slick work Marc.

wot 'e sed.

Cheers Marc!

[jeffc]

Hi Jeff,
You're welcome to add yourself to the spreadsheet now. Just add your name in the first tab and fill in the numbers. You're my Guinea pig
Cheers, Marc

Thanks Marc... guinea pig.. hey I better be careful then to add and not delete..
cheers.. jeffc

[gommer]

Hehe, it seems it turned out OK and you've just made the PCB price drop

[gommer]

New update: price estimate for PSU PCB added (also with auto price update).

Next I want to add the BOM for PSU PCB. Does anyone care to help me with that, as I've missed the discussions on this subject. I don't get any further than 2x LM317...

Cheers, Marc

[Will]

Hi Marc,

I think Jon did a quick BOM in the original HA thread (for the pcb I sent you) - Have a quick look there whilst I see If I can find the right file to generate the BOM for you.

[gommer]

Cheers Will, I'll check it out tomorrow.

[gommer]

Aha, found it here and onwards.

[pingu]

Jun 7, 2013 12:23:50 GMT gommer said:

Aha, found it here and onwards.

Adding a late "Thanks" Marc a really nice bit of work. Well done
Martin

[pingu]

Jun 7, 2013 12:23:50 GMT gommer said:

Aha, found it here and onwards.

Hi,
Not sure if this is any help now but Shaun posted this on the the thread earlier.
If this is the PSU board you are using

H4004 for the bridge (saving my last two SF12 for you know what)
U5/6/7/8 IN4007
C1 470pf 100V
C2/3 2200UF 35V low ESR
C3/8 10UF 50V Suntans . Sorry about the leaning tower of power on the photo.
C4/6 100UF 50V Panasonic FC.
R1/4 100R ½ W
R5/6 Unpopulated
R2/3 2K bourns type multi-turn trimmers
Regs are LM317/337

Read more: rockgrotto.proboards.com/thread/8894/class-pcb-parts-group-buy?page=6#ixzz2WTKwqfmo

Sorry for the late reply have been looking for the list from Shaun it's a bit diffrent from Jon's list.
Hope it helps and not complicates things
Martin

[Deleted]

Martin
A couple of points. I used the SF12 in the bridge rectifier section , and they sounded better than 1N4004 etc. The faster UF400x may be an improvement over the 1N400x though.
I don't recommend low ESR designated capacitors for the PSU filter caps. It's O.K. to have capacitors there that have relatively low ESR, but not stated to be low ESR.
Low ESR capacitors use a different formulation which ensures a very low impedance at 100kHz, but often leads to added sibilance.
With the JLHs, it is best to use a 2,200uF 10V low ESR in parallel with a normal 2,200uF 16V electrolytic on each supply rail for the same reason.

Regards
Alex

[pingu]

Thanks Alex,

1) I used SF14s for PSU, not sure of the caps may have been low ESR not sure will have to check.

2) Yes I used caps as described for the JLH RE but as there is no current limiter first stage I used 4.700Ufs, some one recomended that set up I think somewhere on here

Thanks Alex
Martin

[Deleted]

Jun 17, 2013 13:21:33 GMT pingu said:

Thanks Alex,

1) I used SF14s for PSU, not sure of the caps may have been low ESR not sure will have to check.

2) Yes I used caps as described for the JLH RE but as there is no current limiter first stage I used 4.700Ufs, some one recomended that set up I think somewhere on here

Thanks Alex
Martin

Hi Martin
The SC (Jaycar) HA's JLHs can do without the CL section, and use 4,700uF electros, but the Class A HA/preamp needs the CL section installed, and only 2,200uF capacitors.
To use 4,700uF may result in a Toshiba device overheating during the initial stabilisation period, and possible "hunting" of the output voltage of over plus and minus several millivolts..
Regards
Alex

[pingu]

Hi Alex,
Thanks for the information the couple of JLH's I have built seem stable, at least on a DMM reading to 2 decimal places and all seems cool.
I have run them for a about 10 days on and of at various voltages fron 12v to 20v (+/-), but with no load of course as I have not yey finished the small Brice HA from HFW mag.
I will rebuild the other pair as you suggest to use with this HA including the CL and diffrent caps.

Thanks for the info much appreciated.

Martin