Preliminary Pricing.
I am going to see if Mouser, Allied, Avnet and Digikey will negotiate at all but see the following assuming they dont.
Shinkohs replaced with PRP. Black Gate stays.
Looks like if were were to buy parts one by one as individuals cost would be around 79.80USD for each channel. Add about 10 for shipping and the guess on pcb cost of 7-9 below I think if they were purchase outside of a group buy pricing would be around 185 for stereo if you didnt have to get your own pcbs made.
I dont have pcb quoted yet.I am going to guess 7-9 dollars for the pcb and approx 10 shipping. I think I will charge about 10 for flat rate shipping anywhere in the world. I have to take an approximate weight to the post office and get a few estimates to different countries. Might go down a few dollars on that. I have to include pricing for bags, boxes, tape so maybe it will just stay 10 for shipping and that will probably cover those extras. So assuming 17 for shipping, supplies, pcbs and 52-57 per channel for parts, shipping parts to me and taxes I have to pay I am guessing that a stereo kit (2 channels) would come in at a total cost of about 121. I have some slush in there for lost kits, compensation for me for the time involved, and a 300 dollar donation to DIYaudio. If I have forgotten any parts and need to make additional orders the cost will come out of my compensation. If there are no lost kits to replace there will be more money donated to DIYaudio.
So, I think we are pretty good at guessing 121 including all ... crap, forgot paypal fees. Okay 124 including all fees, shipping, pcbs the whole thing.
If boards come in more or less this will fluctuate by a few bucks and I will let you know. I dont plan to start taking money til April 8th. Two reasons: I am moving and hope to be done moving by the 7th : I want to give you guys time to let me know if you are going to participate in this GB.
Another thing. I obviously sell LDRs to build the Lightspeed. I have some LDR Mount and Balance boards I sell for $8 and matched quads of LDRs I sell for $35. Normally I charge 10 shipping worldwide for any order. For anyone buying in this group buy: If you want to build a Lightpseed all you need is the board/LDRs/100k pot/ 5VDC supply. I will include the LDRs and Mount and Balance board for a total of 30. You dont have extra shipping or extra 13 you would normally pay. So saving about 23 from purchasing some other time. I will also supply the 5k pot, 200R trimmer, 4 limiting resistors free of charge. So thats another 2 dollar or so value.
I just added a column to the spreadsheet so you can place order for the LDRs, etc by marking YES or marking the number you want if you want more than 1 set.
THATS the real Ultimate BOM.
Uriah
I am going to see if Mouser, Allied, Avnet and Digikey will negotiate at all but see the following assuming they dont.
Shinkohs replaced with PRP. Black Gate stays.
Looks like if were were to buy parts one by one as individuals cost would be around 79.80USD for each channel. Add about 10 for shipping and the guess on pcb cost of 7-9 below I think if they were purchase outside of a group buy pricing would be around 185 for stereo if you didnt have to get your own pcbs made.
I dont have pcb quoted yet.I am going to guess 7-9 dollars for the pcb and approx 10 shipping. I think I will charge about 10 for flat rate shipping anywhere in the world. I have to take an approximate weight to the post office and get a few estimates to different countries. Might go down a few dollars on that. I have to include pricing for bags, boxes, tape so maybe it will just stay 10 for shipping and that will probably cover those extras. So assuming 17 for shipping, supplies, pcbs and 52-57 per channel for parts, shipping parts to me and taxes I have to pay I am guessing that a stereo kit (2 channels) would come in at a total cost of about 121. I have some slush in there for lost kits, compensation for me for the time involved, and a 300 dollar donation to DIYaudio. If I have forgotten any parts and need to make additional orders the cost will come out of my compensation. If there are no lost kits to replace there will be more money donated to DIYaudio.
So, I think we are pretty good at guessing 121 including all ... crap, forgot paypal fees. Okay 124 including all fees, shipping, pcbs the whole thing.
If boards come in more or less this will fluctuate by a few bucks and I will let you know. I dont plan to start taking money til April 8th. Two reasons: I am moving and hope to be done moving by the 7th : I want to give you guys time to let me know if you are going to participate in this GB.
Another thing. I obviously sell LDRs to build the Lightspeed. I have some LDR Mount and Balance boards I sell for $8 and matched quads of LDRs I sell for $35. Normally I charge 10 shipping worldwide for any order. For anyone buying in this group buy: If you want to build a Lightpseed all you need is the board/LDRs/100k pot/ 5VDC supply. I will include the LDRs and Mount and Balance board for a total of 30. You dont have extra shipping or extra 13 you would normally pay. So saving about 23 from purchasing some other time. I will also supply the 5k pot, 200R trimmer, 4 limiting resistors free of charge. So thats another 2 dollar or so value.
I just added a column to the spreadsheet so you can place order for the LDRs, etc by marking YES or marking the number you want if you want more than 1 set.
THATS the real Ultimate BOM.
Uriah
Well I got 80 knocked off of the Digikey order. Waiting on a call back from Mouser and Allied. Have to call Avnet.
Uriah
Uriah
I think we can save some cash by using mica pads and shoulder washers with the LM3886 instead of buying the LM3886T which has the insulated case. Steve Slater of ApexJr has the non insulated and we could use the pads and washers with his chips. He does a great service for us and I would like to give him some business.
Uriah
Uriah
Okay folks. Steve Slater cut me a good deal on the LM3886. He is going to include a roll of insulating material that I will cut up for you guys just as we did for the last group buy. I have to find some shoulder washers but those are generally inexpensive on Ebay. So we are saving 51 dollars this way but some of that gets eaten in the shipping to me and shoulder washers. Still, its tax free so thats a bonus and saves an extra 30 some dollars. So this is a good deal for us. Still waiting on Mouser. Probably they will contact me tomorrow.
Uriah
Uriah
Sounds good to me dude, I'm psyched. I have to say, though, that I'd rather uses the LM3886T than add the extra junction of insulation... I can, of course, find them online myself and I have no problem with that.
With the shoulder washer and insulation behind it it is fully isolated from the heatsink. I dont think you should feel that you are putting your amp at risk.
Not worried about electrical insulation, my problem is that I want to use pretty heatsinks ninja'ed from old stereos... and they may not be quite large enough to counter the added thermal insulation of the sheet ;P I'm gonna read the datasheet, have a peek at the sinking recommendations.
The price is lower then I expected for the kit, I am in for a stereo pair now. Nice work on sourcing the parts Uriah, your hard work is really appreciated.
Uriah,
You're doing an excellent job. The cost is really coming down for such a good piece of equipment.
The uninsulated chip used with the pad is not compromised in any way. My chips just don't get that hot, probably because I use a massive heatsink. Instead of a shoulder washer, I use a nylon bolt and nut for attaching the chip to the heatsink. It works great, and there is less risk of distorting the chip by tightening too much against a not perfectly flat heatsink. The nylon gives a little with thermal movement, as well.
URGENT:
There is one important thing to note regarding the Blackgate cap, and I'm sorry I didn't think of it before now. The cap is really big for the space on the board. REALLY big. I had to lay mine over a bit and leave more lead to mount it. No big deal. The bypass cap C21 must be mounted from the bottom of the board, which is not too big a deal--you just need to use longer standoffs (I think 1/2" will be enough) to leave room for it underneath. However, the BG is so big that it also covers some of the space for the input cap, C13. That will be a problem for using the WIMA block style cap you have selected. One solution would be to put the Blackgate under the board and C21 in its normal position on top. That means there must be even more space underneath the board. It can be done, but awkwardly. The other solution is mount C13 off the board completely as mine is, using one of the leads of the cap to connect it to the board. This is a very satisfactory arrangement for a cap with long leads, but won't work with the WIMA. Even the Silmic made for a very tight fit when I used that for C9, so that is not a perfect solution either. The board was designed for a cap the size of a Panny FM. These other caps are all bigger diameter, and it's a tight squeeze. Perhaps a lower voltage cap would be smaller and not as much of a problem, but I'm not sure we want to do that. Any ideas, Dario?
This presents a real dilemma.
Peace,
Tom E
You're doing an excellent job. The cost is really coming down for such a good piece of equipment.
The uninsulated chip used with the pad is not compromised in any way. My chips just don't get that hot, probably because I use a massive heatsink. Instead of a shoulder washer, I use a nylon bolt and nut for attaching the chip to the heatsink. It works great, and there is less risk of distorting the chip by tightening too much against a not perfectly flat heatsink. The nylon gives a little with thermal movement, as well.
URGENT:
There is one important thing to note regarding the Blackgate cap, and I'm sorry I didn't think of it before now. The cap is really big for the space on the board. REALLY big. I had to lay mine over a bit and leave more lead to mount it. No big deal. The bypass cap C21 must be mounted from the bottom of the board, which is not too big a deal--you just need to use longer standoffs (I think 1/2" will be enough) to leave room for it underneath. However, the BG is so big that it also covers some of the space for the input cap, C13. That will be a problem for using the WIMA block style cap you have selected. One solution would be to put the Blackgate under the board and C21 in its normal position on top. That means there must be even more space underneath the board. It can be done, but awkwardly. The other solution is mount C13 off the board completely as mine is, using one of the leads of the cap to connect it to the board. This is a very satisfactory arrangement for a cap with long leads, but won't work with the WIMA. Even the Silmic made for a very tight fit when I used that for C9, so that is not a perfect solution either. The board was designed for a cap the size of a Panny FM. These other caps are all bigger diameter, and it's a tight squeeze. Perhaps a lower voltage cap would be smaller and not as much of a problem, but I'm not sure we want to do that. Any ideas, Dario?
This presents a real dilemma.
Peace,
Tom E
Tom
What if we just put C13, the box Wima, underneath and C21 underneath as well?
I am not overly worried about this as the goal is sound not looks and has been since the first post. You managed. I figure we can manage to. But what do you think? C13 and C21 under the PCB?
Uriah
What if we just put C13, the box Wima, underneath and C21 underneath as well?
I am not overly worried about this as the goal is sound not looks and has been since the first post. You managed. I figure we can manage to. But what do you think? C13 and C21 under the PCB?
Uriah
Uriah, you're an ace.
Ah, the simple solutions are sometimes difficult to see. I love those little inspirational moments when it all appears so clearly.
In fact, the two WIMA caps might even be close to the same height, so sure they could both be mounted underneath. Problem solved. How tall is the input cap you've selected? C21 is really quite small. If C13 is much taller, it could be mounted on its side with bent leads.
I will bet and I sincerely hope that many builders will elect to use a film and foil cap of their choice (or no cap!) with long leads and mount it off the board to avoid the problem anyway, but it's best to have a plan for the standard build first.
Peace,
Tom E
Ah, the simple solutions are sometimes difficult to see. I love those little inspirational moments when it all appears so clearly.
In fact, the two WIMA caps might even be close to the same height, so sure they could both be mounted underneath. Problem solved. How tall is the input cap you've selected? C21 is really quite small. If C13 is much taller, it could be mounted on its side with bent leads.
I will bet and I sincerely hope that many builders will elect to use a film and foil cap of their choice (or no cap!) with long leads and mount it off the board to avoid the problem anyway, but it's best to have a plan for the standard build first.
Peace,
Tom E
Hi Uriah,
I am interested in 2 kits and 2 extra boards. Thanks for doing such a great job for making this possible for all to enjoy. I have added my details to the spreadsheet.
Cheers
Michael
I am interested in 2 kits and 2 extra boards. Thanks for doing such a great job for making this possible for all to enjoy. I have added my details to the spreadsheet.
Cheers
Michael
I am not sure, please correct me if I am wrong, but I think that thermal transfer is better with the uninsulated chip and a good insulating layer than with the LM3886TF. Even that, I would go with the insulated version for convenience. But if not possible, people always can ask for free samples at the National semi. website, or order a pair of them from their usual retailers.
And for the Blackgate issue, could it be possible to make the board a bit bigger, lets say 0,5cm, and so giving the option to use any type of cap?
Uriah option seems to be right too, C13 and C21 underneath, and C9 on top of the board.
Other option is to put the taller C13 on the top, and C21 underneath. Then you can place the C9 Blackgate bending its leads and accounting for the C21 space. Being careful with C9 leads not touching C21 solder side.
The C9 cap, if selected with the 50V rating (Silmic, KZ or BlackGate are identical regarding diameter), is at least 16mm diameter and could be adapted if more space is obtained from C13 and/or C21 and bending C9 leads so that its side sits on the PCB.
In this pic from BlueGTI build you can see that one of those big caps (Silmics in this case) could be mounted:
Mounting C13 on the bottom side could be a solution but standoffs should be very tall...
Two notes:
1- I'll try happily BGs and I expect some improvement too but Silmics aren't muffled or otherwise distorted, absolutely they don't! 😡
Tom changed both C21 and C9 from MKP2/Silmic to FKP2/BG at the same time so the big improvement he heard is from the couple, without changing one cap at a time he simply couldn't know for sure which cap between MKP2 and Silmic gave the unpleasant sound he reported.
Since I've changed only C21 several time comparing the effect of that change using in C9 several caps (Silmics, FMs, Nichicon FGs, Rubycon ZLs) I can say for sure that using a FKP2 in that position give a way more open and detailed sound and it's a great improvement.
The FKP2's effect in C21 is so big that differences between different C9 caps is relatively small...
If BlueGTI is reading he could tell us his impressions on his Silmics MyRef... 😉
2- the input cap:
Pay attention that a lesser cap, like the Wima, in C13 position could simply mask the biggest part of the improvements in sound.
Since now we know an estimate price of 120/130US$ for a stereo kit makes no sense to me using that Wima (2.38$ ea) instead of a Obbligato (8$ ea).
In this pic from BlueGTI build you can see that one of those big caps (Silmics in this case) could be mounted:
An externally hosted image should be here but it was not working when we last tested it.
Mounting C13 on the bottom side could be a solution but standoffs should be very tall...
Two notes:
1- I'll try happily BGs and I expect some improvement too but Silmics aren't muffled or otherwise distorted, absolutely they don't! 😡
Tom changed both C21 and C9 from MKP2/Silmic to FKP2/BG at the same time so the big improvement he heard is from the couple, without changing one cap at a time he simply couldn't know for sure which cap between MKP2 and Silmic gave the unpleasant sound he reported.
Since I've changed only C21 several time comparing the effect of that change using in C9 several caps (Silmics, FMs, Nichicon FGs, Rubycon ZLs) I can say for sure that using a FKP2 in that position give a way more open and detailed sound and it's a great improvement.
The FKP2's effect in C21 is so big that differences between different C9 caps is relatively small...
If BlueGTI is reading he could tell us his impressions on his Silmics MyRef... 😉
2- the input cap:
Pay attention that a lesser cap, like the Wima, in C13 position could simply mask the biggest part of the improvements in sound.
Since now we know an estimate price of 120/130US$ for a stereo kit makes no sense to me using that Wima (2.38$ ea) instead of a Obbligato (8$ ea).
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Does C9 need to be 50v rated, being in the feedback loop? What are the voltages likely to be seen there?
Mauro's BOM for C9 indicates >35V rated caps.
In my MyRef I'm using 35V rated Silmics without any problem.
Attachments
Tom and Dario, if you guys could comment here...
So I think we should be fine populating those few caps under the board. As far as changing the board this is not something I would like to do. Space is at a minimum on this layout, but as Tom and Dario have proven its enough space. I am confident that these Gerber files work as is and changing anything makes me squeamish.
Well, we had quite a discussion previously about C13 and had decided not to go with the expensive input caps and leave it up to the buyer if they want to purchase some exotic for that position. So I removed it from my BOM and didnt replace it with anything, although it had been my intention to do so. So its not included in the price. My mistake here. Happily though the discounts I have been asking of the suppliers will probably cover a WIMA in that position so price should not change for that. Where we can really save a few bucks will be if PCBs come in cheaper than I suspected.
I agree with Dario that a WIMA in C13 may not be the ultimate solution. We have so many opinions on this particular cap and it makes sense that we do. This position is the ultimate sound changer. A good solution here and the amp, any amp, sings. A poor choice here and any amp will sound veiled and weak. Precisely why I DC couple, but we know there are serious risks involved in DC coupling and its not like this particular amp has a trimmer we can adjust to compensate for DC offset on the output. So what we are left with is 3 decisions here. 1: To provide the ultimate cap in this position. 2: To DC couple, with no cap here. 3: To provide a decent cap that allows DC protection.
I have to choose 3 to be fair to the greatest amount of people. I have to make sure no one burns up their speakers and I would feel bad forcing an expensive cap on someone who wants to DC couple. I would also feel bad selling the 'ultimate BOM' with a poor quality cap. So we do compromise in this position to be able to be fair and I take into consideration that we are all DIYers and are all resourceful and will do research and listening to find our favorite solution for C13. I actually feel that putting an expensive cap in there would be a compromise in the spirit of a group buy.
That said.. WIMA in that position is not particularly cheap. Other caps of similar price would be Solen, Clarity Cap, Axon, Obbligato perhaps in quantity. I dont have a problem going around $4 (Obbligato is more but perhaps worth it... lets consider) for this cap. More than that and I think we are starting to get into a realm of pushing something on the buyer.
Solen Solen 2 mfd Fast Cap 400V from Madisound
ClarityCap ClarityCap 2.2 mfd PX Range Polypropylene Caps from Madisound
Axon AXON True Cap Metallized Polypropylene Capacitors
Obbligato Capacitors | Diy HiFi Supply
Humble Homemade Hifi
I would either go with Axon for decent performance and very inexpensive so at least you have good DC blocking and decent sound until you get a much better cap or with the Obbligato for a good cap at a good price. OR we can stick with WIMA.
Hope to hear from Tom and Dario on this.
Got $50 back from Mouser. Barely anything compared to the total cost. But their prices are already very good compared to competitors.
Uriah
So I think we should be fine populating those few caps under the board. As far as changing the board this is not something I would like to do. Space is at a minimum on this layout, but as Tom and Dario have proven its enough space. I am confident that these Gerber files work as is and changing anything makes me squeamish.
Well, we had quite a discussion previously about C13 and had decided not to go with the expensive input caps and leave it up to the buyer if they want to purchase some exotic for that position. So I removed it from my BOM and didnt replace it with anything, although it had been my intention to do so. So its not included in the price. My mistake here. Happily though the discounts I have been asking of the suppliers will probably cover a WIMA in that position so price should not change for that. Where we can really save a few bucks will be if PCBs come in cheaper than I suspected.
I agree with Dario that a WIMA in C13 may not be the ultimate solution. We have so many opinions on this particular cap and it makes sense that we do. This position is the ultimate sound changer. A good solution here and the amp, any amp, sings. A poor choice here and any amp will sound veiled and weak. Precisely why I DC couple, but we know there are serious risks involved in DC coupling and its not like this particular amp has a trimmer we can adjust to compensate for DC offset on the output. So what we are left with is 3 decisions here. 1: To provide the ultimate cap in this position. 2: To DC couple, with no cap here. 3: To provide a decent cap that allows DC protection.
I have to choose 3 to be fair to the greatest amount of people. I have to make sure no one burns up their speakers and I would feel bad forcing an expensive cap on someone who wants to DC couple. I would also feel bad selling the 'ultimate BOM' with a poor quality cap. So we do compromise in this position to be able to be fair and I take into consideration that we are all DIYers and are all resourceful and will do research and listening to find our favorite solution for C13. I actually feel that putting an expensive cap in there would be a compromise in the spirit of a group buy.
That said.. WIMA in that position is not particularly cheap. Other caps of similar price would be Solen, Clarity Cap, Axon, Obbligato perhaps in quantity. I dont have a problem going around $4 (Obbligato is more but perhaps worth it... lets consider) for this cap. More than that and I think we are starting to get into a realm of pushing something on the buyer.
Solen Solen 2 mfd Fast Cap 400V from Madisound
ClarityCap ClarityCap 2.2 mfd PX Range Polypropylene Caps from Madisound
Axon AXON True Cap Metallized Polypropylene Capacitors
Obbligato Capacitors | Diy HiFi Supply
Humble Homemade Hifi
I would either go with Axon for decent performance and very inexpensive so at least you have good DC blocking and decent sound until you get a much better cap or with the Obbligato for a good cap at a good price. OR we can stick with WIMA.
Hope to hear from Tom and Dario on this.
Got $50 back from Mouser. Barely anything compared to the total cost. But their prices are already very good compared to competitors.
Uriah
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I must agree, I'm one of whom would like to see more space on board for C9 and PSU caps but any modification implies prototyping the new pcb and testing that would take much time and price would rise up.
My vote goes to Obbligatos that for decent price, far to be 'boutique', gives an optimum, IMHO, starting point. To get more price would rise up quickly to levels that are unreasonable.
The only exception is Mundorf MCAP Zn (double price) any further improvement requires a 10x price growth.
I really think that with an Obbligato few people would even try to change it.
The PCB should NOT be changed at this time. If we start down that path, this buy will take a lot longer. If someone else wants to undertake a PCB change for themselves in the future, I have a few suggestions, with more space for C9 at the top of the list.
Regarding C13: remember that is does not need to be 2.2mfd. The amp will function perfectly and sound very good with a slightly smaller cap, which would help save money and space.
Don't bother with Solens or ClarityCap. I tried both initially and neither sounded very good. I have not seen anyone else recommend them for this application. They are okay in speakers, but not for low level signals. The Obbligato sounds interesting, and I am willing to try it. If it's not ideal here, it could be salvaged for other uses or sold.
The WIMA is a good, low cost compromise, as it will allow all builders to complete their amps and listen for a while before making changes. I don't know how it will sound because I never tried one, but many commercial amps use them. There are so many other options for C13, and it is the biggest factor in the sound of the amp. Each builder will want a cap that mates with the sound of their system and pleases their own ears. It should be regarded as a tailoring accessory, like cables and other components. That is one of the beauties of building this amp: it is an excellent basic platform for achieving the sound exactly as you want it.
Dario, I am willing to give the Silmic another try when I have extra amps and boards to experiment with. I am quite pleased the kits will include Blackgates, and I would be interested to learn your opinion of them.
How are the varistors working out? Can you give us a part number? The link you provided gave a Maplin part number which means nothing to me. Would this be an item worth including in the kits?
Peace,
Tom E
Peace,
Tom E
Regarding C13: remember that is does not need to be 2.2mfd. The amp will function perfectly and sound very good with a slightly smaller cap, which would help save money and space.
Don't bother with Solens or ClarityCap. I tried both initially and neither sounded very good. I have not seen anyone else recommend them for this application. They are okay in speakers, but not for low level signals. The Obbligato sounds interesting, and I am willing to try it. If it's not ideal here, it could be salvaged for other uses or sold.
The WIMA is a good, low cost compromise, as it will allow all builders to complete their amps and listen for a while before making changes. I don't know how it will sound because I never tried one, but many commercial amps use them. There are so many other options for C13, and it is the biggest factor in the sound of the amp. Each builder will want a cap that mates with the sound of their system and pleases their own ears. It should be regarded as a tailoring accessory, like cables and other components. That is one of the beauties of building this amp: it is an excellent basic platform for achieving the sound exactly as you want it.
Dario, I am willing to give the Silmic another try when I have extra amps and boards to experiment with. I am quite pleased the kits will include Blackgates, and I would be interested to learn your opinion of them.
How are the varistors working out? Can you give us a part number? The link you provided gave a Maplin part number which means nothing to me. Would this be an item worth including in the kits?
Peace,
Tom E
Peace,
Tom E
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