Thanks shoom, that is a great help. It's a few years since I last worked with surface mount components but it was for a commercial outfit at a professional level. I was taught a few tricks at the time which might come in useful again. I used to apply a small dot of solder to one pad then using tweezers to hold the component in place I would heat the end which was sitting on top of the solder dot until it bonded, once the component had cooled down I would then heat the other end while feeding a tiny amount of solder in to the joint. It was neat, fast and reliable. I then went over every joint with a magnifier to check for any defects. I have bought some more cardas quad eutectic solder and a new tip, just need the boards and components now. I am looking forward to this build, I just hope I can do it justice 
Thanks shoom, that is a great help. It's a few years since I last worked with surface mount components but it was for a commercial outfit at a professional level. I was taught a few tricks at the time which might come in useful again. I used to apply a small dot of solder to one pad then using tweezers to hold the component in place I would heat the end which was sitting on top of the solder dot until it bonded, once the component had cooled down I would then heat the other end while feeding a tiny amount of solder in to the joint. It was neat, fast and reliable. I then went over every joint with a magnifier to check for any defects. I have bought some more cardas quad eutectic solder and a new tip, just need the boards and components now. I am looking forward to this build, I just hope I can do it justice
Hi Davy
yes that's the way I do my SMD work.
works well for me.
''I just hope I can do it justice''
you are going to be just fine
Hi Davy
Gods well nice of you to say so but we are all mortals here.
A few more comments on the SMD work.
Just take your time.
I did the chips first as per the superb build guide but I used the flood and suck method.
Soldered one leg each side just to hold it in place and then one side at a time run the iron quickly over the pins applying solder as I went.
Then using solder wick (get a flux pen and soak the wick with flux as the maplins stuff never seems to have enough to remove the solder without using excess heat) soak away and excess solder and then check for continuity on the pins to the track with a multi metre.
Do the same on the other side.
I use a 10x magnification jewellers eye loop to check for shorts.
I’ve used that way with other chips and it’s always worked well.
Just slowly does it
I did the chips for one session and then the rest of the SMD the next day so that eye and hand strain was avoided.
I’m pretty sure that you know this way already but if not then it’s another option.
Soldering the pins individually works well also but I just went with what I know.
This is a superb amplifier so look forward to the listening.
Gods well nice of you to say so but we are all mortals here.
A few more comments on the SMD work.
Just take your time.
I did the chips first as per the superb build guide but I used the flood and suck method.
Soldered one leg each side just to hold it in place and then one side at a time run the iron quickly over the pins applying solder as I went.
Then using solder wick (get a flux pen and soak the wick with flux as the maplins stuff never seems to have enough to remove the solder without using excess heat) soak away and excess solder and then check for continuity on the pins to the track with a multi metre.
Do the same on the other side.
I use a 10x magnification jewellers eye loop to check for shorts.
I’ve used that way with other chips and it’s always worked well.
Just slowly does it
I did the chips for one session and then the rest of the SMD the next day so that eye and hand strain was avoided.
I’m pretty sure that you know this way already but if not then it’s another option.
Soldering the pins individually works well also but I just went with what I know.
This is a superb amplifier so look forward to the listening.
lol, that will teach me to read over what I typo
That sounds like a good method you have going for the chips. I used the drag method in the past but I like to hear alternatives.
I am wary of leaving too much flux beneath surface mount components, I used to get flack for any tiny imperfection but the bloke who contracted me was at times quite shoddy but seemed to get away with it most of the time.
I believe we need to be even more thorough than usual when cleaning up boards with SMD's but then they do tell me that cleanliness is next to godliness
That sounds like a good method you have going for the chips. I used the drag method in the past but I like to hear alternatives.
I am wary of leaving too much flux beneath surface mount components, I used to get flack for any tiny imperfection but the bloke who contracted me was at times quite shoddy but seemed to get away with it most of the time.
I believe we need to be even more thorough than usual when cleaning up boards with SMD's but then they do tell me that cleanliness is next to godliness
I just placed an order with mouser for the BOM , I doubled up for the LM318's and the relays, total cost shipped to the UK = £128.24 They have some of the components on back order so with a bit of luck it will arrive by the time the boards get here from Italy. Just need to save up for transformers and enclosures now.
Not too impressed with mouser, their order sheet total said the price quoted included duty and import tax but when I got the invoice they had added %20 vat to it, is duty not the same thing as vat? I would still have placed the order anyway but I find it all bit misleading Once bitten....
This thread has gone a bit quiet now, hope everything is still on track.
Once bitten....This thread has gone a bit quiet now, hope everything is still on track.
No, they refer to import duties, prices are VAT excluded.
Sure, tomorrow I'll order boards.
Thanks Dario, cant wait to get going on this build now. I ordered the group BOM but am wondering about gain, I have a JC-2 preamp clone at present feeding a chipamp and have to usual problem of the volume going way to loud too fast with only a few degrees rotation of the pot. What is the gain set at for the My Ref and how would I lower it if I have to?
Hi Davy
‘’is duty not the same thing as vat?’’
No
Mouser ship from within the EU ( err sort of) so here in the UK we pay VAT on all purchases from within the EU but no import duties.
Import duties are paid on good from outside the EU (sometimes) which involve a percentage of the total cost of the goods plus a nice big fat handling charge.
To be fair I’d rather pay VAT and avoid the rip off handling charge and have free post with Mouser who I have done business with before.
I’ve found them to be reliable and pretty fast and much faster with them dealing with the charges payable this end.
You’ll have your parts pretty soon which is cool.
Swings and roundabouts but the cost seems like nothing when you hear the amp.
I tried the modular JC 2 (ish) with the FE and had no problem (hum or noise) with too much gain with my speakers (92Db @ 1W)
It could depend on the sensitivity of your speakers also.
What LS have you in mind?
If you do find the gain a bit too much then I’d go for a passive pre (pot in a box or whatever) plenty of idea's on this thread on that front.
As I understand it the gain set up is an important part of the design so maybe Dario can elaborate a little on that front.
‘’is duty not the same thing as vat?’’
No
Mouser ship from within the EU ( err sort of
) so here in the UK we pay VAT on all purchases from within the EU but no import duties.Import duties are paid on good from outside the EU (sometimes
) which involve a percentage of the total cost of the goods plus a nice big fat handling charge.To be fair I’d rather pay VAT and avoid the rip off handling charge and have free post with Mouser who I have done business with before.
I’ve found them to be reliable and pretty fast and much faster with them dealing with the charges payable this end.
You’ll have your parts pretty soon which is cool.
Swings and roundabouts but the cost seems like nothing when you hear the amp.
I tried the modular JC 2 (ish) with the FE and had no problem (hum or noise) with too much gain with my speakers (92Db @ 1W)
It could depend on the sensitivity of your speakers also.
What LS have you in mind?
If you do find the gain a bit too much then I’d go for a passive pre (pot in a box or whatever) plenty of idea's on this thread on that front.
As I understand it the gain set up is an important part of the design so maybe Dario can elaborate a little on that front.
Thanks Shoom, it was the wording on their site which confused me. At present I am still using my diy passive pre (20K pot) to feed the JC-2 so that I can use it's input selector switch. I really like what the JC-2 does and want to use it with the FE if possible. My speakers are 89dB, 6 Ohm Rega R3's. I'm hoping I can get a good diy set built next year sometime. I have a couple of 100K pots, I'm not sure they are suitable but I might try one anyway.
'''22v 300Kv rated transformers''
sounds like a plan to me
BTW
I’ve used my 22v trafo’ed Audiosector to drive my 8ohm PCM FB1+ without issues.
Whether it is optimal is another story but as a good all round choice it seems sensible so long as the new speakers (my woodwork is bad so I tend to buy) that you intend to build have sensible sensitivity and impedance.
I may be wrong though so
Anyone have any thoughts on transformer optimisation?
what Speakers and transformers are others using?
Good points raised and worth going over.
sounds like a plan to me
BTW
I’ve used my 22v trafo’ed Audiosector to drive my 8ohm PCM FB1+ without issues.
Whether it is optimal is another story but as a good all round choice it seems sensible so long as the new speakers (my woodwork is bad so I tend to buy
) that you intend to build have sensible sensitivity and impedance.I may be wrong though so
Anyone have any thoughts on transformer optimisation?
what Speakers and transformers are others using?
Good points raised and worth going over.
Boards have been ordered.
I have ordered some boards more so it's still possible to partecipate.
Good work Dario.
looking forward to building number 2
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