cspirou

Just want to let everyone know that the Song Heui pots fit in perfectly with the boards I received from @sbelyo. A lot of these pots measure pretty well. So unless I'm unless I'm fucking up the measurement I don't really have to return any. I still don't have everyone's shipping address but I'll be messaging you anyway. There is a small number that seem off in terms of resistance but not in terms of tracking. Here is an example of one pot Total resistance: Section 1 - 10.76k Section 2 - 10.77k Section 3 -10.70k Section 4 - 9.76k Series Resistance after turning ~45 degrees Section 1 - 10.51k Section 2 - 10.50k Section 3 -10.44k Section 4 - 9.52k The last section seems way off with 1k difference in resistance. However this is still within the 20% error tolerance specified by Song Heui so still passes their QC. But in terms of attenuation this is the result Section 1 - 32.68 dB Section 2 - 32.01 dB Section 3 - 32.28 dB Section 4 - 32.18 dB This is pretty much spot on. So does it matter if the resistance is off as long as it still attenuates fine?

@chiguy A little update. Most of the testing is done and it seems like I won't have to return much. I'm now organizing packing addresses and should get shipping totals to everyone soon. Message me your shipping address in a PM if you are part of this GB. TKD pots are still open in the meantime

I thought he did post a schematic

How do you plan on testing the pots? I need to do the same thing as well

Update!!: First I want to say sorry that I haven't been on the ball with the TKD pots and updating payment info. Busy because my son was born last week!! But I will start organizing payments on that ASAP. More important though is a package arrived today. I will keep the pots for a week before shipping for testing. Shipping fees will be posted soon. If you would like to skip the testing and get your pots sooner then let me know. I will pick the pots at random and send them to you. If you have a faulty pot then you can try to deal with Hong Seui yourself or you can send them back to me.

I would assume Percy Audio sells the attenuators. Here are the datasheets for the different types http://www.tkd-corp.com/products/att/pdf/cp2500as-e.pdf http://www.tkd-corp.com/products/pot/pdf/cp2500ps-e.pdf Notice the part that says 'circuit method'. The attenuator is more of a ladder circuit whereas the potentiometer is like a variable resistor. The attenuator only has an audio taper but the potentiometer can be log, linear or inverse log. Probably better to order as an attenuator to make it less likely to screw up the order. This is pretty unique to TKD. I haven't seen anyone else that does a variable attenuator like this.

Update Song Heui: I have received an email from Song Heui to inform me that the goods are ready for shipping this Thursday. I will receive a tracking number too when they ship. For testing the pots I will just do matching at certain positions instead of checking the actual taper. I think channel matching is the most important part anyway. Any pots with horrible channel imbalance will be shipped back. This is also a reminder to pay me if you haven't done so yet. Most people have paid the base price but not the additional fees yet. If you think you have paid but I did not update the spreadsheet to credit you then let me know and I'll review my paypal info. Update TKD: I have received a quote on the stereo pots from TKD and have updated the page with real prices. I also checked on the variable potentiometers to see if there was a price difference with the variable attenuators and in most cases there was no difference or a slight increase. So better to stay with the attenuators unless someone really really needs a variable potentiometer. I will leave this open for changes until the end of this week(Nov 11) for anyone that would still like to buy TKD attenuators. Then I'll start requesting payments. Note: I am based in europe so I might change the pricing to euros as opposed to dollars.

What is the max power this can do? Either the mini or the regular one. I read in the thread that it can push 2.5W into 50 ohms class-A. Can you push it further into class-AB or is this purely class-A?

Is there any problem using this board for 4xSE channels as oppose to 2xBAL channels?

I asked last week about their desktop enclosure and got a quote. Although the split body seems like a better idea. The dimensions might not be totally correct but the price should still be valid. I requested quotes for no cutouts as well as 6 holes in front and 5 holes in the rear. I asked for quantities up to 100 but there isn't much difference between 50 and 100 so I'll just go up to 50. P/N & Description: 175DT desktop enclosure 5”W x 6.8”D x 1.720”H, 6 part enclosure, screws included, no cutout, no markings Qty: 1 Price: $213.30 each set Finish: natural aluminum (no finish) Qty: 1 Price: $333.30 each set Finish: black anodize Qty: 5 Price: $85.90 each set Finish: natural aluminum (no finish) Qty: 5 Price: $117.90 each set Finish: black anodize Qty: 10 Price: $66.80 each set Finish: natural aluminum (no finish) Qty: 10 Price: $98.80 each set Finish: black anodize Qty: 25 Price: $54.30 each set Finish: natural aluminum (no finish) Qty: 25 Price: $85.50 each set Finish: black anodize Qty: 50 Price: $44.70 each set Finish: natural aluminum (no finish) Qty: 50 Price: $73.50 each set Finish: black anodize P/N & Description: 175DT desktop enclosure 5”W x 6.8”D x 1.720”H, 6 part enclosure, screws included, with cutouts, no markings Qty: 1 Price: $261.30 each set Finish: natural aluminum (no finish) Qty: 1 Price: $381.30 each set Finish: black anodize Qty: 5 Price: $95.90 each set Finish: natural aluminum (no finish) Qty: 5 Price: $127.90 each set Finish: black anodize Qty: 10 Price: $76.80 each set Finish: natural aluminum (no finish) Qty: 10 Price: $108.80 each set Finish: black anodize Qty: 25 Price: $64.00 each set Finish: natural aluminum (no finish) Qty: 25 Price: $95.20 each set Finish: black anodize Qty: 50 Price: $53.70 each set Finish: natural aluminum (no finish) Qty: 50 Price: $82.50 each set Finish: black anodize

I would prefer it. All the parts on the front panel are fine sticking through without attachment. This means I wouldn't need to worry about the front panels holes being a little too big and I don't need to worry about the top, bottom and sides being exactly 6.8", I can afford to have something a little bit longer without penalty. However this is mainly an issue when shopping around for a stock case. Something custom made shouldn't be too much of a problem.

It's actually not milled but laser cut. I want to try to do something using T-slots It's at lasergist.com and they have 3 mm stainless steel available. 3 mm is also a common thickness for lasercutting wood so I could do wood first for prototyping before doing steel.

I found a site that has some surprisingly affordable stainless steel CNC. I know that most enclosures use aluminum, but is there any particular reason why I shouldn't use stainless steel?

What purpose do these holes serve? Are they for PCB standoffs?

Weird, editing should be open to everyone on the TKD page. I added you and registered your interest.

added

Sorry for taking so long on this. Onto the TKD group buy! Spreadsheet is here This group buy is mainly for balanced 4-gang variable attenuators made by TKD. Note that this is very different from the potentiometers which are more like variable resistors. TKD has no minimum quantities so any item in their current catalog can be ordered. This is what I currently have on the group buy 4CP-601 10k 4CP-2500 10k 4CP-601 50k 2CP-601 10k I only have price quotes for the 4CP-601 and the 4CP-2500 for now. I will also request prices for the stereo attenuators and potentiometers as well. All prices are listed in dollars. Prices for potentiometers are based on the trading price on transferwise.com plus 5% to account for price fluctuations. Any excess amounts will go towards your shipping and related fees so there shouldn't be an issue with overpaying a little. When it comes time for payment you can use paypal but I may also accept transferwise for people paying in a different currency to save a bit on fees. Lead time is between 1.5-2 months. I don't know when to close this group buy but I prefer to do it sooner rather then later due to the long wait. For now I am still gathering interest.

Paid for 3 boards. Thanks!

A little update: Song Heui has confirmed that they have received payment and the gears are in motion. The rep estimated that the order should be complete by Nov 4. When I receive the pots is another matter. I will update on the fees payed on the spreadsheet soon as well as additional information on the TKD group buy. Please let me know if there is anything else you would like to order from TKD and I will add to the GB page. Note that the price for the TKD page is just as estimate based on the exchange rate on google. Real money transfers use slightly higher rates. I'll probably put rates a bit higher. No need to worry about paying excess because it will be applied toward shipping.

Here is the post the email is an image because I don't want bots finding it and sending me spam

I did not get a quote on stereo attenuators. However I have no problem adding it to the GB. We don't need to wait for more people since they do not have a minimum order. Group buys are usually not needed for the stereo pots since they are available on other sites. But a quick check shows that a 2CP-601 pot is about $40 which is more then the 4CP pot for this GB. I would estimate that it would be between the $20-$30 range. Do you want the attenuator or the potentiometer? I was floating between the two and decided on each person since it's low amount to split between everyone. I actually couldn't make up my mind so I flipped a coin.

Update Received the invoice and paid. Delivery date is Nov 30, 2016. Fees for shipping to me and bank transfer will be included and updated in the spreadsheet. These fees will be divided among everyone equally. This should be close to $5 each. Remember that if you are using the goods and merchandise option through paypal to please include a 2.9% + $0.30 for the paypal service charge. Using the gift option will not incur a charge. I should hear back from the manufacturer for an update by next week and will let you guys know about that. But there is not much more to do but wait. In the mean time I will work on a setup to measure pots quickly and accurately to make sure they are within spec. This may delay shipping a little bit but I'd like it if every pot everyone bought is a working pot. When it comes time to ship I will look into shipping all the USA/CAN orders to another member and then have them take care of those order individually. This should be cheaper then individually sending each order from France. Of course if you just want to receive your package faster and pay more, then that can be arranged as well.

I'm sure most people here know but if you missed out on this GB I have my own I am organizing here. If there is a TKD product that isn't listed just let me know and I'll add it.

I did an inquiry on the cost if we decided to do a large bulk group buy. For 1000 pieces the cost is $3.38 each. Buying 15 would be around $50 which is the cost of some individual pots. Plus you don't only have to use them for making Dynalos. We would need about 67 people buying 15 pcs to make this work, but I know there's more than a few people that would buy, 20-50. The bad news is that it would all have to be one type unless they happen to have the material in stock. After this GB is complete and it turns out these pots are pretty good, I'll start a page for a GB with a large minimum order, ending as soon as we reach 1000 pcs. I'll check when we reach 500 pcs just in case. Hopefully this would allow to have enough of these circulating in the "For Sale" section so we don't have to do another group buy like this again. Also someone else sent me another paypal payment without head-case ID. Initials JG. Message me your real name to get credit.

Good news everybody! We've passed the threshold so the order on 99 pots can go through. Those who haven't paid yet should still try ASAP but you won't lose your pots now as long as I receive your payment before the ship date.