PJPro said:
Yes, the ESP one. Although it's quite complex for what it does! Just one thing, Rod Elliott's boards are cheap - it might be best to grab one rather than fiddle round yourself. He's very helpful, too, and provides comprehensive instuctions, plus you get access to more info on his 'sealed site' via password. (in the interests of full disclosure, ESP's boards aren't as neat as many out there, but with the sheer number he produces, who can complain? I don't think any of us can imagine now an internet without ESP, one of the 'go-to's' for information in our hobby.)
Likewise, if you ask Greg Ball on the Ska site, he'll reply within hours, usually. And although a very clever man, he doesn't talk down to you like many do in that position... I'm in contact with him most days via the Ska forum.
Cheers
Stu😉
OK. I think I'll get a few of the soft start circuits from ESP along with the transformer I identified earlier.
I've also bought three Epsilion 24 PCBs to allow me to use anti vandal power switches.
Epsilion 24 Schematic
Bulgin Anti Vandal Switch
If I can, I'm going to power the Epsilion 24 circuit using the transformer provided to power the soft start circuit. Not sure this will be possible. The Epsilion 24 requires 12VAC while the soft start needs 9VAC. I've bought Sigma 24 PCBs just in case (these are usually unavailable, so I don't mind if I don't have to use them for these amps).
I'll get some big caps for DC blocking on the input. I've had a recommendation from Ted205 for Ampohm. Are there any other recommended caps for placing in the signal path?
Also, does anyone have any views on the ferrite beads? Good idea or bad?
I've had a look for inductors. Can anyone have a recommend a particular type? Has anyone used one in their build? The data sheet seems to suggest the inductor is used to counter capacitance due to long speaker cable runs (mine will be short). Will they also serve a RF filtering function? Grateful for any views on inductors.
I've also bought three Epsilion 24 PCBs to allow me to use anti vandal power switches.
Epsilion 24 Schematic
An externally hosted image should be here but it was not working when we last tested it.
Bulgin Anti Vandal Switch
If I can, I'm going to power the Epsilion 24 circuit using the transformer provided to power the soft start circuit. Not sure this will be possible. The Epsilion 24 requires 12VAC while the soft start needs 9VAC. I've bought Sigma 24 PCBs just in case (these are usually unavailable, so I don't mind if I don't have to use them for these amps).
I'll get some big caps for DC blocking on the input. I've had a recommendation from Ted205 for Ampohm. Are there any other recommended caps for placing in the signal path?
Also, does anyone have any views on the ferrite beads? Good idea or bad?
I've had a look for inductors. Can anyone have a recommend a particular type? Has anyone used one in their build? The data sheet seems to suggest the inductor is used to counter capacitance due to long speaker cable runs (mine will be short). Will they also serve a RF filtering function? Grateful for any views on inductors.
Hi PJ,
I went into the ESP secure site (not 'sealed'
) and had a look for you. The relays have a 12V coil, and are rated at 10A (SPDT switching). Rod uses ones marked FRM1-1C1 which he describes as having a universal footprint. If you Google this number you get plenty of hits.
FYI.
Stuey
I went into the ESP secure site (not 'sealed'
) and had a look for you. The relays have a 12V coil, and are rated at 10A (SPDT switching). Rod uses ones marked FRM1-1C1 which he describes as having a universal footprint. If you Google this number you get plenty of hits.FYI.
Stuey
Well, my intention is up upgrade them over time by using discrete amp circuits and improved power supplies.....while keeping the transformer, switch and soft start the same. So, I'm keen to get the bits I'm not going to change right first time.Stuey said:
Moreover, it gives me a chance to experiment and to try and understand/experience as many different circuits as possible in the run up to building a B22 headphone amp with a Sigma 22 power supply and (in my dreams) a brace of B24 power amps.
Incidentally, I've got a Starving Student headphone amp kit arriving any day now from Beezar. I like these kits cos everything you need is supplied in the kit. Makes life a lot simpler 🙂. See here.
An externally hosted image should be here but it was not working when we last tested it.
Starving Student kit by Beezar.com
Thanks Stuey. But a quick search on Farnell and RS didn't return any hits!Stuey said:Hi PJ,
I went into the ESP secure site (not 'sealed'
FYI.
Stuey
I think these may suffice. They simply need the same footprint and ratings.
http://www.jaycarelectronics.co.uk/productView.asp?ID=SY4050&CATID=28&form=CAT&SUBCATID=754
Edit: I just realised the 2C2 is a DPDT and that photo on Jaycar is just indicative, so that IS the right one IMO. See the link below where the -2C2 is rated at 2 x 5A (ie. douple pole) and both types have the same photo. So I'd suggest the -1C1 is the SPDT variant 1 x 10A which is what you need. Note Jaycar used the same photo for the DPDT, cat no SY 4052.
http://www.dt.com.au/category.php?cat=ELECT:COMP:RELAY
Many of the Aussie electronics businesses (like ESP) buy from Jaycar wholesale (called Electus) further suggesting that this might be the one.
Stuey
http://www.jaycarelectronics.co.uk/productView.asp?ID=SY4050&CATID=28&form=CAT&SUBCATID=754
Edit: I just realised the 2C2 is a DPDT and that photo on Jaycar is just indicative, so that IS the right one IMO. See the link below where the -2C2 is rated at 2 x 5A (ie. douple pole) and both types have the same photo. So I'd suggest the -1C1 is the SPDT variant 1 x 10A which is what you need. Note Jaycar used the same photo for the DPDT, cat no SY 4052.
http://www.dt.com.au/category.php?cat=ELECT:COMP:RELAY
Many of the Aussie electronics businesses (like ESP) buy from Jaycar wholesale (called Electus) further suggesting that this might be the one.
Stuey
anatech said:
Interestingly, that won the Grand Prize for the best design idea for 2001...and the designer won $1,500!
Hi Stuey,
As a subscriber to that magazine (EDN), would have hoped that they also judged the designs on whether they were acceptable or not if you actually attempted to pass equipment for safety certification. They normally have great ideas, thought provoking at least.
You know what this situation proves? Safety organizations are a necessary evil simply to protect everyone from others who simply can't see beyond the end of their pencil.
Hi PJPro,
Those are great looking buttons, but last time I checked, they were a tad bit expensive. Really nice switches though.
I think you have the right idea there. To take stock of what your overall plans are, and how you will work towards them through time.
As far as capacitors go, reasonable film types will be better than a tantalum or electrolytic. Stay away from stacked ceramic! Generally speaking, the lower the K of the dielectric is, the better sounding the capacitor should be - within reason. That is a very general guide. Also watch the dielectric absorption, that you want to keep low as well. Don't sweat it though, caps are easy to change, and you may find that the differences between some are not audible.
-Chris
That's the part that's killing me. This guy who designed the circuit did have an inventive idea for sure. The problem is that he didn't let safety stand in the way of his ideas. I sure hope he didn't have anyone put that circuit into operation!
As a subscriber to that magazine (EDN), would have hoped that they also judged the designs on whether they were acceptable or not if you actually attempted to pass equipment for safety certification. They normally have great ideas, thought provoking at least.
You know what this situation proves? Safety organizations are a necessary evil simply to protect everyone from others who simply can't see beyond the end of their pencil.
Hi PJPro,
Those are great looking buttons, but last time I checked, they were a tad bit expensive. Really nice switches though.
I think you have the right idea there. To take stock of what your overall plans are, and how you will work towards them through time.
As far as capacitors go, reasonable film types will be better than a tantalum or electrolytic. Stay away from stacked ceramic! Generally speaking, the lower the K of the dielectric is, the better sounding the capacitor should be - within reason. That is a very general guide. Also watch the dielectric absorption, that you want to keep low as well. Don't sweat it though, caps are easy to change, and you may find that the differences between some are not audible.
-Chris
Agreed. But I want to get nice switches right from the start and avoid modifying the equally expensive front panels.anatech said:
I assume you are refering to the input caps. OK. I'll have a browse, perhaps on other forums, to see what's being used. I'd rather hoped that others would have experimented and found ones which best suited the chip amp.....although I understand these things can be very personal.anatech said:
Chris, do you have a view on the ferrite beads as recommended by infinia. I don't doubt his word. I'd just like a second opinion. Failing that, I'll just buy them and experiment. I'd also be grateful for a steer on the inductor.
Thanks.
Stuey said:
Thanks Stuey. If I can track down something appropriate it'll help me narrow down a suitable component here in the UK.
OK. The ESP soft start boards are ordered. I'll wait until I've read the accompanying notes before I start to order any of the required components.
Hi PJPro,
Off the cuff, most plastic dielectric types will commit fewer sonic evils than electrolytic or ceramic types may. I was trying to give you the tools to determine your local availability and whatever the future holds. I was not trying to be cryptic at all.
Epcos does make some good ones for example.
Generally speaking, if you are passing any DC current, you want a gapped (EI) core. If the current will be AC only, a toroid might be a good bet. There are instances where toroid transformers have problems in AC supply for power due to "effective DC " caused by line waveform distortion. Personally, anything to do with AC power gets an EI core part in my reality.
-Chris
Yes.
Off the cuff, most plastic dielectric types will commit fewer sonic evils than electrolytic or ceramic types may. I was trying to give you the tools to determine your local availability and whatever the future holds. I was not trying to be cryptic at all.
Epcos does make some good ones for example.
I fully support what he has said. My own experience over time confirms that this is the best approach. A ferrite bead is not going to cause sonic problems. There isn't enough current flowing here to cause any non-linearity to occur. Give the RF an easy path to ground and a more difficult path into your equipment.
Inductor for where?
Generally speaking, if you are passing any DC current, you want a gapped (EI) core. If the current will be AC only, a toroid might be a good bet. There are instances where toroid transformers have problems in AC supply for power due to "effective DC " caused by line waveform distortion. Personally, anything to do with AC power gets an EI core part in my reality.
-Chris
Hi Chris.anatech said:
See the following quotes for the history on this, which stemmed from the filtering power inlet modules and other sources of RF.
Juergen Knoop[/i] [B]......rf will enter your amp at the other 'inputs' (audio in + speakerout) too.... [/B][/QUOTE] [QUOTE][i]Originally posted by infinia said:
PJPro said:
Ted205[/i] [B]L1 is an inductor. Have alook at the lm3886 datasheet under reactive loading [/B][/QUOTE] [QUOTE][i]Originally posted by PJPro said:
The datasheet can be found here, with the reference to inductors on page 20.
Hopefully the above quotes will give you a quick way to understand where I am coming from. Thanks for any advice you are able to provide.
1) L1 construction is in the ESP link I provided (handwound air coil around resistor body). Hang it off the PWB to the output jack or a standoff.
2) search DIYA -solid state forum for individual posts using terms like "inductor+zobel+RFI" if confused after reading go to step 3).😉
3) It's included in National Semis test circuits and it's the right output circuit/network to use consisting of 4 parts.
4) It looks pretty cool too.😎
2) search DIYA -solid state forum for individual posts using terms like "inductor+zobel+RFI" if confused after reading go to step 3).😉
3) It's included in National Semis test circuits and it's the right output circuit/network to use consisting of 4 parts.
4) It looks pretty cool too.😎
PJPro said:
Hi PJ,
That Jaycar link IS in the UK - it's their UK mail order site. 😉 That's why I tried their UK site (a mirror of the Aussie one). I think they have a presence there nowadays.
You'll get access to the ESP secure site once you've ordered. The page for Project 39 has VERY comprehensive info, including a very clear drawing of how to wire it up to the switch and IEC socket.
Cheers
Stu
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