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GB for DC coupled B1 buffer with shunt PSUs

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Joined 2006
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I would like to suggest that the final package for the boards come with a sheet (maybe we can collectively put that together here) with some of the gotchas and recommended practices. The thread is long enough now that it's a real pain finding (and not overlooking!) important information.

Here are some suggestions:
- issues with potential shuttering problems: list of suggested solutions
- how to measure IDSS for the sk170 to put "the right one" in the "right spot"
- how to measure the LEDs (and mixing is allowed, for example) to get the right total

What others along these lines do we have?

My experience with the revC GB was that lots of questions like this came later because we didn't put together a sheet like that.

Thoughts?

peter

Peter,
always good ideas.
I usually pack with a sheet of paper anyways, so I can a print off some common tips. I prefer someone wrote a builders guide with some of these tips, URL's to posts etc. I will have my hands full on other matters, so would rather leave it to a better scribe. I recommend it be a shared document that we can post to the google shared pages for review. It's more lon-linear than this forum. afiak.
I dont think it needs to be complicated, just a few pics, URLS and comments, maybe a faq sheet. Like faq- dont use your dads faucet solder and blow torch to assemble this device.
I could print the quick guide and ship it along.
 
My costs for a Mezmerize:
Mouser - caps, connectors, switch, etc. 19.00
Antek - 2x15VAC 50VA toroid 13.00
Parts Connection - Resistors 7.00
TechDIY 2SKs and mosfets 40.00
LDRs 39.00
Assorted stuff I forgot 12.00
PCB (assumed) 6.50
_______
Total $136.50 USD

Paid a lot for the transistors! Did not include shipping.
 
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What are your caps exactly? As for LDR, cost is optional. So around $100 kicks you off. And at about $125 includes a Grufti's choice SMD Vishay resistors switcher pot from epay. A tip from me is that a common carbon $1-1.5 22k stereo log with metal body, pleased me more than a conductive plastic Bourns. The shunt 220k helps its channel balance. If someone has to go 50k because of a small output cap of his source for instance, must go 560k instead of 220k input shunt resistor. Read more there.
 
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Still no tonal aberrations or detail shortage judging from your reports. But you are Lightspeed boosted we must not forget. Lightspeed would be best for those who wanna max it out. But not for the fainthearted. I see you all still flog the monster but it fights back sometimes in the LSPD thread. Is there a conclusion of where to set it at least for the DCB1Shunted?
 
Still no tonal aberrations or detail shortage judging from your reports. But you are Lightspeed boosted we must not forget. Lightspeed would be best for those who wanna max it out. But not for the fainthearted. I see you all still flog the monster but it fights back sometimes in the LSPD thread. Is there a conclusion of where to set it at least for the DCB1Shunted?

I have not figured it out quite yet. I need to hit the breadboard for a bit till I get a better handle on it. I hope to have it sorted and decent recommendation for folks soon, perhaps a week.
 
diyAudio Chief Moderator
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A little Led info. I run a little test on red, green & yellow, under 2Vf Leds. If with a DVM that gives them under 1mA on diode Vf test (not all got such function), the reds add up +20% Vf at 6mA, the greens +10%, the yellows +13%. So you can measure 2-3 from each color of your stash and see if they follow each other's gain VS 9V battery +1k test (mine did), match with the DVM but know the final total by jotting down the Vf % climb at more mA. 6mA isn't random, I have seen that 2SK170s hover around 70% of their 9-10V Idss when under 0,6Vbe. Because the bulk of BL from Spencer seem to fall between 8-9mA Idss, 8.5*0.7=5.95. Hope this helps.
 
Actually I am putting off dinner right now messing with a jig to test them for Vgs. Am using a LME49710, a few 10k resistors, 10V regulated and of course the DUT. Getting around .37039VDC on this one right now. Have a question in to a master guru on Vgs, guess who :), and if he confirms that this is the way to go then I will say yes to testing them. Give me a day or two to be sure.
I am absolutely sure on the LDRs. I can supply these. No problem.
Uriah
 
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Joined 2006
Paid Member
Okay,
I got the details of the costs of the boards sorted out.
I am upgrading the Hypnotize to gold plating from tin. I tried to keep pricing near the original GB effort but cannot do so without running below budget initially. The difference here is the prototype board costs that were sent out was a significant charge into the GB. I have amortized that out. After 100 boards the boards should generate a small profit and that will be going to DiyAudio forum.

The costs of the Hypnotize is 5.50 USD each.
The cost of the Mesmerize is 6.50 USD each.

Shipping for 1-4 boards is $5.00
Shipping for 5-9 boards is $7.50
Shipping for 10+ boards is $10.00

The end date for the group buy will be October 11th. If 100 boards each are not met, then the GB will stay open a bit longer.

Paypal Information is in the Google Spreadsheet
Please don't send personal messages with questions, as my Inbox has been getting too full often, a personal email is better. Thanks.