mwl168

Got it. Thanks!

I am sourcing the power transformer for the +/- 15V regulator for KGSSHV. Can I use a dual secondary transformer configured as a center-tapped transformer by joining one wire each from the two secondaries to form the center tap? Anyone sees concerns of doing so? Or better yet, anyone has a Mouser part number that you recommend for this part? Thanks!

It was the S5277G I was not sure about. Thanks!

S5277G and Z1100 diodes are both obsolete. Can someone recommend current production replacement? Preferably Mouser stocked parts - I am about to place a big order with Mouser for a KGSSHV build. Thanks!

Thanks Craig and all. This is very good to know. Kevin: Do you mean 7721-3PPSG as this one ? http://www.mouser.com/ProductDetail/Aavid-Thermalloy/7721-3PPSG/?qs=sGAEpiMZZMu6TJb8E8Cjry%252brZ0Ynb0Cb Mouser part number 532-7721-3PPS

Thanks Birgir!

So essentially move R104 to between C108 and the bias pin of the output jack?

Good point about the thread stripping. I assume the standoffs do not need to be peek material?

Apologize for the ignorant question; Does one need to use peek nuts with peek screws in this application? The only reason I ask is the cost - those peek nuts are expensive.

Thanks Birgir. I'll have to fabricate it on a perf board then. To confirm the right way to convert the SRD-7 to run on Pro bias (580V): 1. I disconnect the factory bias portion of the original circuit after the 150K resistor and neon bulb. 2. Construct the bias circuit of the SRD-7 Mk II in post #6 but skip C108 and change R104 to 4.7M. Thanks again for your help!

Thanks Birgir. Do you still have the custom PCB you made for this modification available? I checked your website but did not see it.

To be clear, are you saying that the SRD-7 MK II schematic was wrong and that R104 should be 4.7M and C108 should be at a different position in the circuit.?

I am a bit embarrassed. I did google it and came across this image but did not know it's what I was looking for ) Thanks Birgir! Edit: For reference for others that may be interested in this topic, here is the normal-bias SRD-7 schematic.

Hi Birgir: Resurrecting an old thread. I have a SRD-7 I am thinking about converting to Pro bias to fill in while I build my KGSSHV. The link you posted in this thread is broken. Any chance you can link me to a schematic? Thanks!

Really great work. Thanks for the internal photos.

It reminds me of Goldmund preamps. Also the Spectral preamps made in the 90's (I think). Never heard the Spectral but a couple of Goldmund preamps I listened to were very nice sounding gears. Nice build. It looks very slim. Does it use shorter heatsinks or it's an optical illusion? Some interior photos would be great!

I am out. Thanks!

I am a maybe - again depending on the cost.

Hi All: We are slightly ahead of schedule. I have received all but one confirmation payment so I went ahead and placed our order with SeeedStudio. I am happy to confirm that we have secured the free-shipping discount and I have received order confirmation e-mail from SeeedStudio. As I mentioned in my earlier post, it's Chinese New Year break over there and their normal work schedule will resume around next Tuesday, Feb. 24. I will post updates on this thread to keep everyone informed of the progress and status. Also, I checked with USPS and found out that they have a flat-rate, padded envelope, priority mail option which comes with tracking and $50 insurance for domestic US shipping. It ends up being about $1 more than the USPS first class mail option that I have originally planned to use. This only applies to the continent US shipping address. I suggest we use this service for those with US shipping addresses. PM me if you have objections. For the non-US location, I will have to wait till we receive the boards for USPS to weight the package and quote me shipping charge. Best!

Thanks for your interest. I'll put you on the waiting list.

I think the kgsshvpsminifinalstn9360 board can accommodate both KSA1156 and STN9360. The STN9360 will need to be mounted vertically while observing the pin out specification. See Kevin's post #4014 in this thread. Although I can use additional clarification about the use of 270V zener with KSA1156. It would be great too if someone can share some insights of the pro and con between the choice of the two devices.

This GB is officially closed. Thanks all for your interest, quick responses and participation. Anyone post with their interest for the board set from this point on will be put on the waiting list - please refer to the first post in this thread. I have good news for those participating in this GB. Since the GB was expanded and we will now be ordering 15 sets, the price per set is dropped to $23 USD before shipping from SeeedStudio. Since we should qualify for the free shipping from SeeedStudio (would have been another $63+), the only additional cost for the GB participants will be shipping cost from me to you and the PayPal fee. For comparison, it would have been $43 USD per set if only 5 sets of boards were ordered. Here is the list of GB participants: mypasswordis (2 sets), iwik, johnwmclean, chinsettawong, insanity, eggil, GeorgeP, kingofsnake, ChrisX, DefQon (2 sets). I will PM all of you with confirmation and my PayPal account. I need to figure out the proper amount for your down payment to me now that the per set price has dropped. This amount will be stated in my PM to you. If no one has objection, I like to move up the timetable and ask that you PayPal me the down payment by end of day Saturday, Feb 21 so I can put our order in the following day to secure the free-shipping discount. If this presents a difficulty for you, please PM me. Please let me know if I missed something. Best!

One set is 2 offboard amp PCBs (1 per channel) and 1 PSU PCB (see my first post). Below is the rough dimension of the boards. I cannot be certain - waiting for confirmation on the kgsshv thread. kgsshvampv16mini (amp): 182mm x 86mm, kgsshvpsminifinalstn9360 (PSU): 176mm x 167mm If someone has this information please confirm or correct me. DefQon, are you still in for two sets? (my bad, I had previously miscalculated number of participants)

Hi ChrisX: You are in - if I was not clear in my last post. Hi DefQon: As eggil stated, this GB is for the off-board version. Are you still interested? Thanks!

Wow! Thanks guys for your quick responses. This is going way faster than I expected. I have also received PM for boards as well. I am expanding the volume to 15 sets and closing the GB now. That means everyone posted in this thread is included. I will follow up with additional details soon!