(AK) Class A HA PCB and parts Group Buy

[Deleted]

Thought this might interest builders.
http://s1100.beta.photobucket.com/user/drymdrum/media/Toshies-1_zps6fab87e3.jpg.html?sort=3&o=0

Toshiba 2SA1930 and 2SC5171 from Kessler in Germany at £00.58 each which includes the delivery to UK.

www.kessler-electronic.de/Halbleiter/Transistoren/2_SC/2SC5171_i9_1036_0.htm



Mouser UK is an even better deal 200 for £54.40 works out at 27.2p each orders over £50 delivery free

uk.mouser.com/ProductDetail/Toshiba/2SA1930QM/?Toshiba/2SA1930QM/&qs=EEns8I54Y6CqHlOjFshF6g==

[Deleted]

That's a wicked find Alan.
Thanks for sharing.

[XTRProf]

Feb 22, 2013 13:33:29 GMT drymdrum said:

Thought this might interest builders.
http://s1100.beta.photobucket.com/user/drymdrum/media/Toshies-1_zps6fab87e3.jpg.html?sort=3&o=0

Toshiba 2SA1930 and 2SC5171 from Kessler in Germany at £00.58 each which includes the delivery to UK.

www.kessler-electronic.de/Halbleiter/Transistoren/2_SC/2SC5171_i9_1036_0.htm



Mouser UK is an even better deal 200 for £54.40 works out at 27.2p each orders over £50 delivery free

uk.mouser.com/ProductDetail/Toshiba/2SA1930QM/?Toshiba/2SA1930QM/&qs=EEns8I54Y6CqHlOjFshF6g==

Hi Allan, Chris or anybody,

If you guys wanted to buy some of those stuffs from Mouser UK with free shipping, I have some XOs to buy too so that you can reduce your amount of 1930 and 5171 togather with my XOs for free shipping.

Can we take this offline by PMing me instead.

Thanks.

[gommer]

Hold your horses guys,

I'm going to post a summary here this evening and i'd like to know who's really interested in group buying components and/or matched transistor pairs or quads. Mouser was already on my list, as I'm assembling a BOM.

Cheers, Marc

[XTRProf]

Feb 22, 2013 16:14:52 GMT gommer said:

Hold your horses guys,

I'm going to post a summary here this evening and i'd like to know who's really interested in group buying components and/or matched transistor pairs or quads. Mouser was already on my list, as I'm assembling a BOM.

Cheers, Marc

If it's free shipping, I can join you too in your Mouser UK buy for my XOs, Marc. In fact anybody living in a place with a good postal system for redistribution worldwide.

[gommer]

Allright, let's get this ball rolling.

Here's what i picked up from this thread so far:

Pre/HA PCB
gommer x4
shaun x4
will x4
juke x2
cj x2
pingu x4
Spirit x4
______________

LS352 & LS313
gommer x4
drymdrum x4
shaun x 4
pingu x4
spirit x4
______________

PS PCB
gommer x6
Spirit x4
pingu x5
______________

parts
gommer x4
Spirit x4
pingu x4

Chris, Syd, Will, are you guys in for the LS devices? We're already at 20 pieces each, so that's fine as it is. But if you want them, please add yourselves to the list.
PS PCB's will probably also go through, as 15 is enough in order to have a half decent price.

On the parts front, things are meager. But remember, transistor matching is only possible with large numbers. Is everyone buying 20-50 parts for his own stock?

Here's the partlist that i would look for, per HA PCB (all caps film, Wima polyprop or polyester for the larger values)

2SA1930	x1	68pF	x1
2SC5171	x1	100pF	x1
7815	x1	100nF	x8
7915	x1	1µ	x1
BC327	x1	3µ3	x1
BC337	x1
BC547	x2
BC549C	x1
BC557B	x1
BC558B	x1
BC559	x1
OPA134	x1
SF12	x1

So, let's hear your voices and add to the list or let us know that you've looked, but show no further interest.

Cheers, Marc

[Deleted]

Hi Marc

You’ve been busy

For my part I’m only up for boards and LS devices as I’d prefer to do my own matching transistor wise.

All part of the fun

But

Thanks for the generous offer it’s much appreciated

Take care

[Deleted]

Hi Marc
Please add my name for 2 PCBs. I will either earmark them for possible future use, or they will be available for any late Aussie starter.

Kind Regards
Alex

[Deleted]

Hi Alex

good idea

i have two of my boards penciled in for the late Euro mob.

take care

[Deleted]

Here's the partlist that i would look for, per HA PCB (all caps film, Wima polyprop or polyester for the larger values)

Hi Marc
Don't forget the 2.2nF addition to the offset corrector.
Regards
Alex

[XTRProf]

I will put in 2 XOs order later as it's very hard to compose using this bloody HP browser app.

[Spirit]

Looks good to me, thanks Marc

[Deleted]

Hi Marc,

I'm OK for the LS devices and I think I have a couple of Jaycar PSU kits too but may cherry pick from the parts list after I've had a good rummage in the parts box!

Cheers

[Will]

Hi Marc,

I'm in for two sets of LS devices please, and perhaps some other pieces, I need to check as well.

The bc327/337 could do with being the higher hfe -40 versions, to make up for the toshibas, which have been on the low side recently. Defo up for matched quads of them!

[Deleted]

iThe bc327/337 could do with being the higher hfe -40 versions, to make up for the toshibas, which have been on the low side recently. Defo up for matched quads of them! nsert quote here

I wish they would sort out these niggly forum bugs . Often it sees "Enter" as "Reply"
I suggested the 25 version with minimum HFE of 160, or even the 40 version for the same reason. My latest batch is lower HFE than previoius batches too.
Kind Regards
Alex

[PinkFloyd]

Feb 23, 2013 21:05:57 GMT @sandyk said:

iThe bc327/337 could do with being the higher hfe -40 versions, to make up for the toshibas, which have been on the low side recently. Defo up for matched quads of them! nsert quote here

I wish they would sort out these niggly forum bugs . Often it sees "Enter" as "Reply"
I suggested the 25 version with minimum HFE of 160, or even the 40 version for the same reason. My latest batch is lower HFE than previoius batches too.
Kind Regards
Alex

I hope you sort it out with Ian

[Deleted]

I hope you sort it out with Ian

There is nothing to sort out with Ian.
It didn't happen.
Alex

[Deleted]

Feb 23, 2013 16:17:25 GMT Will said:

Hi Marc,

I'm in for two sets of LS devices please, and perhaps some other pieces, I need to check as well.

The bc327/337 could do with being the higher hfe -40 versions, to make up for the toshibas, which have been on the low side recently. Defo up for matched quads of them!

I'll check and let you know tomorrow, thanks Marc.

Syd

[XTRProf]

My order:

To decide 4X Matched LS devices after knowing price
2X Crystek 49.152 MHz HCMOS 3.3V TCXO (Mouser P/N: 549-CCHD-957-25-49.1 Manufacturer P/N: CCHD-957-25-49.152)


Thanks

[pingu]

Hi Marc,

To go back to your post 535 the answer is yes in for boards and GB of bits.

Thanks

Martin

[Deleted]

Hi Marc

I'd like to join the parts GB, enough for the four boards. I don't need LS or PSU boards.

Thanks again,

Syd

[gommer]

Thanks for confirming/replying guys, I'll update the participants list later on.

First something else:

		Matching		Mouser			Farnell
2SA1930	x1	1,3		2SA1930(Q,M)
2SC5171	x1	1,3		757-2SC5171(Q,M)
7815	x1			MC7815CTG
7915	x1			MC7915ACTG
BC327	x1	2,3		BC32716TA	BC32725BU	BC32740BU
BC337	x1	2,3		BC33716BU	BC33725BU	BC33740BU
BC547	x2			BC547BBU
BC549C	x1			BC549CTA
BC557B	x1			BC557BTA
BC558B	x1			BC558BTA
BC559	x1			BC559BTA
LS313	x1	4
LS352	x1	4
OPA134	x1			OPA134PA
SF12	x1						SF12
68pF	x1			FKP2O100681D00JSSD
100pF	x1			FKP2O101001D00JSSD
2n2	x1			FKP2D012201D00JSSD
100nF	x8			MKS2F031001E00JSSD
1µ	x1			MKS2C041001F00JSSD
3µ3	x1			MKS2C043301K00JSSD	MKS2B043301H00KSSD
100µ	x6			UKT1V101MED	UPJ1V101MPD
500R MT	x2			3296W-1-501LF
SK129	x2						SK-129-50,8-STS

If you'd like to take a look at the selected components, that would be nice.
Multiturn trimmer selected is bourns because it's sealed and only slightly more expensive. I've selected 2 100µF elco's not sure what to choose and if there's better out there (not too critical I suppose)/

Last point, I've indicated which transistors should match, either NPN/PNP pairs or gain pairs. I could identify input and output stages. But I'm not sure about the middle part, which are gain and which only current source. Help is appreciated here.

I'll soon continue with components for the PS boards. I'll go for the dual PS with heat sinks on the PCB.

[Will]

Hi Marc,

In my build, I matched all transistors between both pcbs, as well as selecting the 3v3 zener for 3.3v at the correct rail voltage. Jon went further and matched caps as well! All good if you want the surety of the best build you can do.

A couple of points - the BC549C should be selected for hfe around 500 - 550 according to Alex's original notes. Also, as you most likely know, if you are buying transistors to match, then you need to buy a large pool and so will end up with 'wastage' or unmatched parts. Given the cost of the LS devices this will be VERY expensive, so although something that would be wanted if money was no object, I would suggest just buying-and-supplying for these. Of course, others might be happy to go ahead and buy a load of LS devices and go for matching and a share of the 'unmatched'

[gommer]

Hi will,

Matching between PCB's would grant equal distortion, phase, timing, gain,... between left/right. But are there other matches needed on a single PCB? Some transistors are cheap enough to buy 100 of them.

A few quad matches within 2-3% should be in them. Maybe even more in ammo pack or tape and reel, in contrast to bulk.

Cheers, Marc

[Deleted]

Hi Marc
It's the front end of the HA/preamp where the magic happens, mainly due to those very well matched LS devices.
Try to get the BC549C VAS transistors in both modules with similar HFE too.
The actual HFE isn't that critical, but don't be tempted to use some with VERY high HFE. 450 to 550 works well.
It's nice to have well matched output devices too, as it has been shown elsewhere that measured distortion is lower.
I wish that I had taken up the earlier offer of matched output devices, but the simple expedient of boosting the gain of the output stage in that half by using a higher gain BC327or BC337
in conjunction with the lower HFE output device appears to work well.It's best to use.1% MF resistors in the emitters of the LS352, but careful selection of normal 1% types will do the same.
It's the matching between them that is important, not their actual measured value as you will be well aware.
Kind Regards
Alex