|
Post by PinkFloyd on Jun 15, 2011 21:22:30 GMT
Hi Frans,
I am pulling out at the last minute.... WAY too much on my plate at the moment and it would be a shame to deny somebody who really wants a board one so please allocate my board to someone else.
If you want feedback (from me) then you could send over a working example and I will be more than happy to have a good listen.... So busy at the moment.
All the best,
Mike.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 15, 2011 22:37:00 GMT
Hi Frans, If I'm not too late and if I've not P'd you off too much, if the price of the board alone is US$24.99 can I take up Mike's PCB please. I plan to store it until funds are replenished later in the year. Cheers, Dave.
|
|
|
Post by Garage1217 on Jun 18, 2011 4:01:59 GMT
Got my board in Frans, it is NICE! Well done. Cannot wait until I have the time to put this baby together!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 19, 2011 18:45:00 GMT
Mike I will let have Dave the board. He has PM.
Only 'tubesurf' has not 'claimed' his board yet. If he doesn't in the coming weeks this board will go to the next in line, which would be 'tobm'.
|
|
|
Post by gommer on Jun 19, 2011 18:54:22 GMT
Frans, how many are on the waiting list now?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 19, 2011 19:56:10 GMT
after tobm.... only you.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 28, 2011 21:42:05 GMT
Last board has been claimed too.
3 requests for a next batch... will need 10 at least
|
|
joethearachnid
Been here a while!
Old head on young shoulders.
Posts: 380
|
Post by joethearachnid on Jun 30, 2011 14:05:08 GMT
Been thinking about enclosures (because I like planning things even if I can't afford them) and I was wondering whether you could fit everything into a Hammond 1455T2201 (223 x 160 x 51.5mm). From some rough workings (laying the PCB and some roughly transformer-sized bits onto a sheet of paper) I think that either everything would fit perfectly or not quite fit at all. The real issue would be the front and rear fittings, and how much space they take up.
Apart from that, the Hammond to me has a number of advantages: it's cheap, relatively attractive and also has a removable plate that would make changing jumpers a cinch with a little 'creative editing' of the original front/back panel design.
-JoetheArachnid
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jun 30, 2011 14:14:22 GMT
|
|
joethearachnid
Been here a while!
Old head on young shoulders.
Posts: 380
|
Post by joethearachnid on Jun 30, 2011 14:44:10 GMT
The main issue for me is the two trafos. Most enclosures could handily fit the PCB and one 15VA toroid, but with two it starts to get a little cramped. If I did get a Galaxy I'd probably go for the 230x170 or 230x230 case. But with VAT and shipping it comes to near £40 vs. the £26 for the Hammond from Rapid.
-JoetheArachnid
|
|
|
Post by bjarne on Jun 30, 2011 21:18:07 GMT
I'm more concerned about the drilling and engraving the enclosure! Do you have contacts that could do that? Maybe we should also group up in the BOM-Thread?!
|
|
joethearachnid
Been here a while!
Old head on young shoulders.
Posts: 380
|
Post by joethearachnid on Jun 30, 2011 22:48:35 GMT
I have a handy pillar drill (drill press) for the drilling duties and an old-fashioned metal rule for getting everything lined up and even. Any 'engraving' would probably consist of my missing the headphone socket whilst half asleep and then scratching the faceplate with my jack.
-JoetheArachnid
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 1, 2011 8:25:15 GMT
I had some time yesterday to start with the easiest part (and cheapest), resistors and diodes: I also have some of the transistors, a few caps and DIL sockets, the rest will have to wait until we go ahead with the GB. PS. I didn't see the soldering wire was there when I took the, crappy, pic
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 18, 2011 16:04:14 GMT
I received some BC556B for the power supply section to check for proper Vbe voltage. Turns out these do not zener at the desired range (7.2 to 7.6V) but at 10.7 So I went ahead and gathered all PNP transistors and measured them all. aside from a few odballs most were either 7.3V, 7.6V, 9.1V or 10.7 depending on manufacturer and type (BC556B or BC557B)
Now they need to be between 7.2 and 7.6 and must not be outside this range. All MUST be from the same manufacturer/batch. In this case they all have (almost) exactly the same voltage.
For those that have not mounted these 8 transistors (the ones in the PS section not those in the protection circuit) let me know and I will send you a set of 8 (Vbe matched) transistors and 8 diodes (1N4148) for this position and all will be well (F.O.C.).
For those that bought a PCB Please P.M. me
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 21, 2011 20:37:16 GMT
I got impatient today and built up the components I have so far. I hope it checks out alright. The four transistors T9 etc look odd sitting diagonal but it seems to be what's required, I hope. Not very hi-res but maybe that's as well. Best, Syd
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 21, 2011 20:59:42 GMT
The +16V and - 16V were not meant to have jumpers. Nor the grounding pins. (that's why they don't fit very well, the spacing is smaller than 2.54 mm. On page 2 you can see how the power supply pads have been soldered. After measuring the power supply voltages (+ and - 16V) you just put a small wire in it (I didn't even do that) and pore a blob of solder across the pads.
The BF245 transistors should not be diagonal but if the pins are in the proper holes it doesn't matter. Mine are not diagonal and have no idea why yours came out that way they, should simply be opposite to the transistors that are already in there (as can be seen in the manual pictures) It seems to be coming along nicely and besides the 2 remarks it looks promissing.
The 6 audio IC's should not be mounted before the PS voltage have been checked.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 21, 2011 22:20:00 GMT
Thanks Frans. I saw JP numbers on the layout sheet and wrongly assumed jumpers needed. I did wonder, but then I often do until things come clear , extraction will commence... This a pic of the Data Sheet for my 245s ex Farnell. The Atlas tester also showed gate as pin 1 so have I correctly identified the right hole on the PCB for the gate? If so all is well. Syd
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 27, 2011 22:11:23 GMT
Javier spotted an error in the layout of the board.
positions C48 and C49 have been swapped. C48 (10nF) must be close to IC13 (NE5534A) and C49 (100nF) close to IC14 (BUF634).
Another thing that is not right is the S from the FET pictured above, this should say G. If you mount it as it is displayed on the PCB layout (in the same manner as the transistors next to it) it will work O.K. so don't mind the S on the PCB.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 30, 2011 11:36:38 GMT
Current state of my C.H.Amp's board: As I've run out of part I won't be able to continue until September. Still pending: - Zener diodes - 9V Relay - LED - LED's resistors - LED header - 1 x NE5534 I broke accidentally
|
|
mrarroyo
Been here a while!
Our man in Miami!
Posts: 1,003
|
Post by mrarroyo on Jul 30, 2011 12:59:23 GMT
Javier, instead of buying "vino" buy parts!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 30, 2011 13:13:10 GMT
Just completed, except for LED and opamps. I'll stop at this point and re-read Frans' manual before installing those! Javier, that's a shame, getting so close, then a month's delay. Syd
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 30, 2011 13:59:52 GMT
Javier
I'm not sure if your opamps are soldered in or just set in for the pic but in Post 90 frans said
"The 6 audio IC's should not be mounted before the PS voltage have been checked".
Apologies if you are aware of that.
Syd
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 30, 2011 14:33:51 GMT
The power-up procedure explained. The BUF634 and 5534A must be soldered directly onto the PCB. This needs to be done before initial power-up / testing of the power supply circuit. HOW TO:The +16V solder pads and -16V solder pads for both channels need to be 'open'. Once they are connected the power supply voltage is connected to the amplifier part. While unconnected the power supply is not connected to the amplifier part. - For safety reasons I would not insert the 6 audio opamps yet (they go in the IC sockets) - Take notice the powersupply has a softstart feature so the output voltage will have to stabilise for a few seconds before you start your measurements. Next, connect a transformer to the AC inputs (mind the phase !) Each of the 2 big capacitors (next to the connected transformer) should have around 24V on it (may deviate a few volts, not an exact voltage) next step is to check the power supply voltages: put the black lead of your multimeter on the GND pad (between the small caps next to the +16V and -16V pads) Set the meter on 20V DC (unless you have an autoranging voltmeter) Put the red lead on the +16V pad. This must be the pad closest to the NE5534A (the pad on the right in the picture above) This should read around +16V (may be between +15V and +16,5V) and write down or remember the voltage. Next: keep the black lead on the GND pad. Put the red lead on the -16V pad. This must be the one closest to the NE5534A (the one on the right in the picture above) This should read around -16V ( may be between -15V and -16,5V) and write down or remember the voltage. What's important is that both of these voltages should be close together in absolute value. For instance both 16.28V for example +16.28 V and - 16.30 V is acceptable. If they are within +/- 0.025V it is O.K. The same procedure needs to be performed for the other channel. Connect the trafo to the other channel and repeat the procedure above. In case the voltages are not correct this must be solved before the audio-opamps are inserted. Feel free to contact me if a problem has risen.When all voltages check out O.K. power the PCB down and empty the reservoir caps. Next put a small piece of wire between the power pads close together or simply 'pore' a blob of solder so the pads that are close together make contact. a small piece of wire is prefered though and solder that piece of wire. This must be done for all 4 powersupply bridges. After this procedure we can check proper operation of the amplifier (do not connect headphones yet) We will cross that bridge once the first builder has reached this stage.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 30, 2011 15:53:33 GMT
MiguelI don't buy any vino from june to october, only beer + Gin & tonic , too hot for vino unless is "dressed" as in cold sangría ;D. 35ºC (95ºF) right now with a "real feel" of much more. I stop because I'm going away on holidays for the whole month, Jon has all needed remaing parts so no worries, it'll be finished as soon as I come back. @syd The "audio" ICs are the ones that go in the sockets, those will stay out until is safe to put them in (V<16.5). @frans I think I understood the voltage checking part but I don't quite get the grounding part. Can you explain in easy to understand terms what needs to be done? I got this socket but I have no idea wether it is isolated or not and if it can be used for grounding: es.farnell.com/neutrik/nj3fp6c/socket-1-4-jack-panel-locking/dp/212180?Ntt=212-180
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 30, 2011 16:58:42 GMT
AFAIK it is not grounded but is easily checked with a multimeter. Simply measure Ohms between the ground (common) lug and the metal housing. If there is no continuity it is isolated. It is the locking kind so you have to push the red button if you want to pull the HP plug out. So in your case (a not grounded HP plug) you can solder a blob (or small connection wire) on JP5 and JP6. In this case, the casing is grounded with the left 2 M3 holes, so the PCB holes need to make proper physical contact with the metal housing at least at those 2 points. Should there for some reason be a ground loop (very unlikely) you can always replace the JP5 and JP6 connection with 1k resistors.
|
|