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Interested in getting started with DIY builds, don't know where to start


chocolates
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Hi all, I've been more and more interested in building my own amp after having built a relatively simple Elekit amp. I've been reading through the KGSSHV and KGSSHV Carbon build threads and I think I've found the google drives for the schematics and various documents, but it's still a bit confusing where to begin, and I'm not entirely sure I should jump right into trying to build a KGSSHV Carbon. I'm also unclear where one sources the PCBs for any of those builds - seems like various members hold extras and there are some floating around on eBay of dubious origin.

Anyway, I'm not exactly certain what build would be good to start out with, or what the differences are between the various builds, or which ones (besides the Carbon) still have active support around them. Could I get a little bit of direction of where and how to start? I do have soldering experience and I know my way around a multimeter. I don't mind RTFMing - just can't seem to find the manual to begin with!

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1 hour ago, chocolates said:

Hi all, I've been more and more interested in building my own amp after having built a relatively simple Elekit amp. I've been reading through the KGSSHV and KGSSHV Carbon build threads and I think I've found the google drives for the schematics and various documents, but it's still a bit confusing where to begin, and I'm not entirely sure I should jump right into trying to build a KGSSHV Carbon. I'm also unclear where one sources the PCBs for any of those builds - seems like various members hold extras and there are some floating around on eBay of dubious origin.

The pcb files are in zips with the contents in a format called gerber which can be uploaded to a pcb manufacturer like jlcpcb. The gebers contain all the necessary information for the creating the copper tracks, drilling of holes, silkscreen printing etc. Often there are minimum order sizes of around 5 of each type of board so often people have spares...

 

1 hour ago, chocolates said:

Anyway, I'm not exactly certain what build would be good to start out with, or what the differences are between the various builds, or which ones (besides the Carbon) still have active support around them. Could I get a little bit of direction of where and how to start? I do have soldering experience and I know my way around a multimeter. I don't mind RTFMing - just can't seem to find the manual to begin with!

There are no step by step instructions. There is an assumption that you can read a schematic, are prepared to read through some very lengthy forum threads and do basic drilling for mounting boards to heatsinks etc. the information is a bit spread-out.

In general you need:

BOM - bill of materials to get the right value and size components. Downloads from the appropriate forum thread for your build (and possibly two threads - the second thread being for the power supply)

schematics - for troubleshooting etc in the forum threads and or download from https://drive.google.com/drive/folders/0B7egryukiT7_TFlEQlBRejdVdDQ

the gerber files for getting the pcbs made in the forum threads or download from https://drive.google.com/drive/folders/0B_iJFfZStuVhSE5nOHBVdTByR1k

the specifications for the transformers. in the forum threads.

advice. in the forum threads and ask in the threads.

in general the markings on the pcbs takes precedence over the schematic or bill of materials (unless the pcb has a silkscreen error).

Some amps have more information than others -  the threads grow organically over time depending upon popularity, etc.  

In general support is available for everything on a voluntary basis. You post questions on the appropriate thread hope for someone to answer. There are some very knowledgeable and helpful people active in the forum for example Kevin Gilmore, Kerry, JoaMat. Often the people who created the design will answer questions in the forum posts or people who have actually built one or even modified one.

Unless you have lots of money/luck/ or existing stocks of obsolete components obtained from known good sources, I would stay away from any design which requires no longer manufactured transistors. There are many fakes floating around which can and will fail catastrophically on first switch on and non fakes are rare and there are few trusted sources willing to sell to non friends.

I would advise reading the forum threads from start to finish and making notes, that way you can see the different versions/modifications emerge, see issues with certain components for example in the DIY T2 thread the voltages are high enough that some makes of resistor sparked and the insulation broke down.... Look at what people did that worked or did not work and learn from their experience.

Finally if you can, give as well as receive. Post what works for you, post pictures, post updated bills of materials etc.

 

 

 

 

 

Edited by jamesmking
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One thing I recommend is to watch a few of Youtube videos on soldering technics if you have not already done so. Pace put on a few videos that I like very much.

Electrostatic amps like the Carbon operate on very high voltages which makes them rather unforgiving with less than tedious soldering job. In many threads here you will find information about cleaning solder flux, etc. that are good practice to follow. 

I would further recommend getting good quality soldering station and solder. It’s very good investment for serious DIYers.
 




 

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19 hours ago, jamesmking said:

I would advise reading the forum threads from start to finish and making notes, that way you can see the different versions/modifications emerge, see issues with certain components for example in the DIY T2 thread the voltages are high enough that some makes of resistor sparked and the insulation broke down.... Look at what people did that worked or did not work and learn from their experience.

It’s like being an archaeologist I imagine, very welcome @chocolates!

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On 3/28/2021 at 9:20 PM, mwl168 said:

One thing I recommend is to watch a few of Youtube videos on soldering technics if you have not already done so. Pace put on a few videos that I like very much.

Electrostatic amps like the Carbon operate on very high voltages which makes them rather unforgiving with less than tedious soldering job. In many threads here you will find information about cleaning solder flux, etc. that are good practice to follow. 

I would further recommend getting good quality soldering station and solder. It’s very good investment for serious DIYers.
 




 

good soldering technique and understanding what is going on when you solder: (a little wordy, somewhat dated and slow paced but the latter part of the video has lots of useful info).

I heartily agree a good quality temperature adjustable soldering iron is essential and it will make soldering easier, more consistent and you will get better joints. Something along the lines of the hakko fx888d (although the use interface is horrible) that has descent power and is reliable and has repeatable temperatures.

also good quality solder

and good quality flux

I would add a good quality multimeter, one that will not blow up in you hand if say by accident try to measure a 400V psu rail when the meter is in resistance mode... and yes I am speaking from experience here.... I was tired had already lecturer for 9 hours that day. its not cheap but I really like the brymen BM869s. - or one of the lower end models they seem to be very well made and robust. If the multimeter supports temperature probe(s) all the better for verify transistor case temperatures are not excessive etc.

joe smith one you tube has done some excellent videos comparing and torturing multimeters for reliability and high voltage tolerance.

 

for proper verification of stability, checking for clipping, etc a signal generator and scope are necessary. For a signal generator the bare minimum would be the analog output of a sound card on a pc and some software to generate sine waves, triangle and square. 

given the high voltage outputs and rails the scope needs to have switchable x1 and x10 probes (x10 is actually divide by 10 so you can get 400V down to a more manageable 40V). Scopes can be dangerous to use since the ground wire on the probes is actually earth referenced and is clipped to something in the circuit which is not at earth potential you get the possibility of a short to ground....

Some form of desordering to 1. fix mistakes, 2 make repairs. The cheap option is solderwick or a spring loaded desoldering pump. The far more expensive option is a desloldering station. For me using a soldering iron and solder wick has resulted in to many lifted tracks and is too slow and clumsy. something like this works well and is worth its weight in 2sj79s. There are many similar types out there. it is temperature controlled and has a vacuum pump to suck out the solder.

For safety a variac is also very useful it allows you to slowly increase the voltage going into the psu so that if there is an issue it would hopefully manifest at lower voltages and hence reduce the collateral damage

 

 

 once you get more serious a transistor tester and identifier can be very useful especially to check for bad components or to post mortem when the "magic smoke comes out". It can also do small signal transistor and led matching.

 

if you are going to do any surface mount soldering there are multiple ways to do it. fine tip soldering iron, hot air station, reflow oven. Magnification is useful - . The cheap ones can be really uncomfortable and can slide off your head easily but if your eyesight is not 20/20 I find them essential for surface mount and for generally inspecting joints etc.

 

now some "luxury" items to make life easier etc

The duoyi allows you to test high voltage zeners and also aids in detecting fake old stock transistors by providing non destructive transistor breakdown voltage testing. The instruction manual is crap and the sockets are junk. But with some modifications it works well.

another luxury is an LCR meter - this can allow you to match capacitors and inductors and also can measure lower capacitances e.g. a few PF than a multimeter can manage. It can also measure the effective series resistance of caps and other parameters so you can compare caps and identify worn out caps in old equipment.

 

super luxury items because you are addicted to building: distortion analyser

 

super luxury? ultrasonic cleaner. flux residue can result in joints degrading over time and at the voltages some stax amps work at e.g. the T2 the residue can conduct and cause failures.

super luxury: sometimes the provided gerbers are the wrong shape, don't fit your style and you wish you could change them. Sprint allows you to import gerbers, modify and re-export. Its relatively cheap.

https://www.electronic-software-shop.com/lng/en/electronic-software/sprint-layout-60.html?language=en

super luxury: sometimes you want to make your own schematics:

https://www.electronic-software-shop.com/lng/en/electronic-software/splan-70.html

 

super luxury: hands free thin probes for smd or when you don't have 3+ hands available. (The same company also sells hands free multimeter probes).

disclaimer, all items shown here I own personally and use regularly. However, other builders may have their own favourites and peoples priorities and build styles vary. So these are suggestions and nothing more.

Edited by jamesmking
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4 minutes ago, jamesmking said:

For me using a soldering iron and solder wick has resulted in to many lifted tracks and is too slow and clumsy.

This may be a matter of technique because I've had very little trouble using a wick to desolder components. It only really gets tricky when a pin is attached to a ground plane or similar, but if it's just one pin that will rapidly sink heat like that, it's no big deal since you can just do it last.

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15 minutes ago, Fitz said:

This may be a matter of technique because I've had very little trouble using a wick to desolder components. It only really gets tricky when a pin is attached to a ground plane or similar, but if it's just one pin that will rapidly sink heat like that, it's no big deal since you can just do it last.

I agree a lot comes down to how much you are going to build and your budget... however sometimes solderwick cant cut it.

I once soldered an octal socket on the wrong side of a 2mm 2oz copper board.... solderwick that out 😱 desoldering station to the rescue, board and socket survived. the socket was ptfe round pin with tight pcb holes. 😬

 

Edited by jamesmking
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Depends on how tight the clearance is in the holes, if it's not super tight it'll be a pain because you waste a ton of wick but will come out without too much work. A cheaper socket with flat pins will be ez pz to get back out, while one with round pins that just barely fit, yeah that'll suck trying to get out with wick. I can't say that I've ever actually put a large component on the wrong side before though.

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Nice post with YouTube video clips above, James.

One tool I’ve found very useful is desoldering gun. I use DEN-ON SC7000Z. The first one I bought nine years ago and it still working. Last year I bought a second one. DEN-ON isn’t cheap but it’s very reliable and it’s said to be possible to get spare parts if needed.

There are different tips available and with the 1.5 mm I’ve desoldered the small 9 pin Teflon tube holder with ease.

Another good thing with the DEN-ON is hot air blowing. With hot air blowing I remove smd parts. A few days ago when doing 0402 parts soldering exercise I tested to remove a few 0402 parts and that worked great. Then I put the parts back – good exercise...

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