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Post by jphoward on Mar 27, 2009 5:38:56 GMT
Well, I'm now the proud owner of a JLR PSRR PCB (thanks Spirit!), and have fitted all the resistors and the small transistors. I'm working off the 'v2.1 (No Current Limiter) September 2008' layout. 1st thing to mention: it looks like there's an error in that doc. The 1u5 capacitor in the top-right is shown a bit too high, so it's connecting to the collector, rather than the base. And now some questions: - What type of capacitor can I use for the 1u5's? Jaycar have RM-7172, 1.5uF 23mm MKT, which should work OK, but it's very clunky to try to fit it. There are greencaps which are a better fit (especially the 1uF RG-5170) - would they be suitable? There's also ceramics, but they're only 50V... would that be enough?
- For the 10uF and 100uF capacitors, I've got 16V ones at the moment, since that's what Spirit has listed in his parts list, but I see in Alex's they're specified as min 25V. Is 16V going to be enough? Does it matter whether or not they are ESR? (I know the 2200uF should be)
- Is the orientation of the heatsink in the component layout correct for the BD series, or the Toshibas? (I believe they have their heatsinks on opposite sides, right?)
Just an FYI for those looking to buy the parts for this - the 16V 2200uF capacitors from Jaycar are a bit on the large side, so go the 10V ones if you can.
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Spirit
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Post by Spirit on Mar 27, 2009 5:45:13 GMT
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Post by jphoward on Mar 27, 2009 6:11:32 GMT
Actually, please ignore the question about the 1u5's - I see now the note that mentions that 1u - 2.2u electrolytics can also be used, so I'll just do that instead.
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Post by Deleted on Mar 27, 2009 7:12:05 GMT
Well, I'm now the proud owner of a JLR PSRR PCB (thanks Spirit!), and have fitted all the resistors and the small transistors. I'm working off the 'v2.1 (No Current Limiter) September 2008' layout. 1st thing to mention: it looks like there's an error in that doc. The 1u5 capacitor in the top-right is shown a bit too high, so it's connecting to the collector, rather than the base. And now some questions: - What type of capacitor can I use for the 1u5's? Jaycar have RM-7172, 1.5uF 23mm MKT, which should work OK, but it's very clunky to try to fit it. There are greencaps which are a better fit (especially the 1uF RG-5170) - would they be suitable? There's also ceramics, but they're only 50V... would that be enough?
- For the 10uF and 100uF capacitors, I've got 16V ones at the moment, since that's what Spirit has listed in his parts list, but I see in Alex's they're specified as min 25V. Is 16V going to be enough? Does it matter whether or not they are ESR? (I know the 2200uF should be)
- Is the orientation of the heatsink in the component layout correct for the BD series, or the Toshibas? (I believe they have their heatsinks on opposite sides, right?)
Just an FYI for those looking to buy the parts for this - the 16V 2200uF capacitors from Jaycar are a bit on the large side, so go the 10V ones if you can. The heatsinks and Toshiba devices face the opposite way around to the original SC layout diagram. Forget DSE for the 3 pin terminal block. The majority of their stores no longer carry such stuff. Jaycar HM3173 is also suiutable.:CAT. NO. HM3130 RRP $1.20 2 WAY 5.08MM WEIDMULLER PCB MOUNT SCREW TERMINAL These are 5.08mm spacing, come in 2 and 3 way, are interlocking and orange in colour. QTY: 1+ $1.20,10+ $1.05 The only low ESR electrolytics should be the Jaycar RE-6306 2,200uF 10V The 1.5uF capacitors may still be available from DSE online for around $2 each,or perhaps ordered in to local store .. Cap MKT 1.5 uF 63 VDC Polyester Film 155K (K=10%) Cat. R3038 $2.00 each 470pf capacitors should be 100V minimum rating.
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Post by jphoward on Mar 27, 2009 12:56:06 GMT
The heatsinks and Toshiba devices face the opposite way around to the original SC layout diagram. We might be talking about different things... my questions were all related to the JLH PSRR, which doesn't (AFAIK) have an SC layout diagram. As I mentioned in my post, I'm working from 'v2.1 (No Current Limiter) September 2008' (which you were kind enough to send me!). Which way around should the trannies go in this board?
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Post by Deleted on Mar 27, 2009 13:21:06 GMT
Jeremy Sorry. The reference to the heatsink threw me. Too much time in front of the P.C. lately ! Looking at the front of the Toshiba devices. (label side) the pins from left to right, are Base,Collector, Emitter.The Emitter pin goes into the hole with a tiny "e" next to it on the copper side of the PCB Alex
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Post by jphoward on Mar 27, 2009 22:03:24 GMT
Thanks for explaining, Alex. I figured that's how they are oriented, but I wasn't sure - I tried looking up the datasheet (there's a 1st time for everything!) but I couldn't work out from the diagram which way round their example was meant to be! I don't think those datasheets are drawn to be consumed by normal humans...
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Post by jphoward on Mar 28, 2009 14:02:07 GMT
I'm in heaven. Both PSRR's are now done, and I've spent the last few hours listening to the one connected to my Transporter. In Julia Fischer's rendition of Tchaikovsky's Violin Concerto (88khz lossless recording from hdtracks.com) the characteristics of her particular instrument are clearly audible, and the subtleties of her playing really come out. In 'One Of These Days' (track #1 off Pink Floyd's 'Meddle') the individual notes of slap bass line and clear and distinct, and Gilmour's powerful slide guitar cuts through strongly. Other music I auditioned included Madelaine Peyroux, Diana Krall, and Borodin's String Quartet #2 (Takács Quartet), and in each case I got more out of the recording than I have ever before. I'm using the BD-series trannies at the moment in the PSRR, since I haven't received the Toshibas from WES yet (although I have already got Toshibas in the amp itself) - so I understand there's still some room for improvement. I may also try one of audio-gd's discrete modules down the track... but this would be just as an experiment - I'm already entirely thrilled with the sound I'm getting! Many thanks Sandyk for the clearly written instructions and all the help, and Spirit for the PSRR PCB (which was very nicely made - good job!).
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Spirit
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Post by Spirit on Mar 28, 2009 14:32:38 GMT
Not a worry mate Glad you're enjoying it so
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Post by Deleted on Mar 28, 2009 21:00:43 GMT
I'm in heaven. Both PSRR's are now done, and I've spent the last few hours listening to the one connected to my Transporter. In Julia Fischer's rendition of Tchaikovsky's Violin Concerto (88khz lossless recording from hdtracks.com) the characteristics of her particular instrument are clearly audible, and the subtleties of her playing really come out. In 'One Of These Days' (track #1 off Pink Floyd's 'Meddle') the individual notes of slap bass line and clear and distinct, and Gilmour's powerful slide guitar cuts through strongly. Other music I auditioned included Madelaine Peyroux, Diana Krall, and Borodin's String Quartet #2 (Takács Quartet), and in each case I got more out of the recording than I have ever before. I'm using the BD-series trannies at the moment in the PSRR, since I haven't received the Toshibas from WES yet (although I have already got Toshibas in the amp itself) - so I understand there's still some room for improvement. I may also try one of audio-gd's discrete modules down the track... but this would be just as an experiment - I'm already entirely thrilled with the sound I'm getting! Many thanks Sandyk for the clearly written instructions and all the help, and Spirit for the PSRR PCB (which was very nicely made - good job!). jeremy I'm glad you like the results so far. I was wondering where you were going to squeeze in the JLH, but you obviously managed. O.K. Do you have any problems with low end "slam" or think it sounds too laidback? Alex
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Post by jphoward on Mar 28, 2009 21:23:39 GMT
I was wondering where you were going to squeeze in the JLH, but you obviously managed. O.K. Actually I haven't put the lid back on the case yet - currently the JLH is hanging over the edge. I'll have to reorganise things a bit to fit it in... I might even need a new case. My ATH-AD700 'phones are viewed by some as a bit light on the bass, although in my view it's just because they actually get it right, whereas many are 'boomy'. With the SCHA+JLH, the low end is now tighter, which these headphones really seem to need. I definitely wouldn't call the low end 'laid back'. With headphones more bassy than mine, there may be a problem with low-end 'slam' - I'm playing tennis all day today, but when I'm back I'll try some of my other 'phones and see if I see any issues.
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Post by Deleted on Mar 28, 2009 21:27:25 GMT
I was wondering where you were going to squeeze in the JLH, but you obviously managed. O.K. Actually I haven't put the lid back on the case yet - currently the JLH is hanging over the edge. I'll have to reorganise things a bit to fit it in... I might even need a new case. My ATH-AD700 'phones are viewed by some as a bit light on the bass, although in my view it's just because they actually get it right, whereas many are 'boomy'. With the SCHA+JLH, the low end is now tighter, which these headphones really seem to need. I definitely wouldn't call the low end 'laid back'. With headphones more bassy than mine, there may be a problem with low-end 'slam' - I'm playing tennis all day today, but when I'm back I'll try some of my other 'phones and see if I see any issues. Jeremy Thanks for the reply. Have you thought about making a couple of small L shaped brackets, and mounting the JLH on it's side ? Alex
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Spirit
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Post by Spirit on Mar 28, 2009 21:54:04 GMT
Actually I haven't put the lid back on the case yet - currently the JLH is hanging over the edge. I'll have to reorganise things a bit to fit it in... I might even need a new case. Alternatively, if you wanted to file down the edges a little more, you could probably take 3-4mm off them... I was in a rush to get them sent (+ had assignments to do), so I didn't file them down as much as I would have liked... ;D
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robertkd
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Post by robertkd on Mar 28, 2009 23:27:28 GMT
My ATH-AD700 'phones are viewed by some as a bit light on the bass, although in my view it's just because they actually get it right, whereas many are 'boomy'. With the SCHA+JLH, the low end is now tighter, which these headphones really seem to need. I definitely wouldn't call the low end 'laid back'. With headphones more bassy than mine, there may be a problem with low-end 'slam' - I'm playing tennis all day today, but when I'm back I'll try some of my other 'phones and see if I see any issues. Interesting comments I guess it's all down to personal preference but for me I agree the AD700's have more then enough low end for me . Robert
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Post by jphoward on Mar 29, 2009 11:56:24 GMT
Have you thought about making a couple of small L shaped brackets, and mounting the JLH on it's side ? Great minds think alike! Unfortunately, when I tried that, it didn't fit. See the pics thread to see my eventual solution (which unfortunately required moving the PSU and shield).
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Post by jphoward on Mar 29, 2009 12:16:57 GMT
I'm playing tennis all day today, but when I'm back I'll try some of my other 'phones and see if I see any issues. I'm back - thrashed by my wife for the 2nd time in 2 weeks I've tried out my Etymotics ER-6i's and the SCHA really shows their flaws. The non-flat response of these 'phones is well known, but it hadn't really bothered me until now. Anyway Alex, apropos of your question - with these headphones there's a heck of a lot of 'slam' in the low-end. I got 1/2 way through track #4 of Pink Floyd's 'The Wall' and couldn't listen any more - it was quite painful. I also tried out the headphones I use while motorcycling: ' Earmolds'. I've always found these most satisfactory while out on the road, and also when flying. However I didn't have high expectations in a more serious audition. Frankly, I was extremely surprised by how well they did. None of the problems I had experienced with the Etymotics, and I listened to most of 'The Wall' because I was enjoying it so much! They only fell down when I tried them on Julia Fischer's rendition of Tchaikovsky - there was some odd background low-frequency 'wind noise' in the quieter sections. But there was no bass problems at all. So Alex, I think the answer to your question is "it depends"...
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Post by rbrook on Apr 6, 2009 13:17:48 GMT
Hi guys,
I've just got all the parts to build my JLH (current limited version) but i have a question about the current limiter transistor.
The schematics i have says to use a 2SA1930 but i have the spare BD140 from the SCHA so i was going to use that as its only limiting the inrush current (is that right). But looking at the tracks on the board it looks like the collector and emitter are in the wrong spots (the collector is the middle pin incoming power and emitter is outgoing power, right?)
Cheers, Richard.
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robertkd
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Post by robertkd on Apr 6, 2009 13:22:24 GMT
Hi guys, I've just got all the parts to build my JLH (current limited version) but i have a question about the current limiter transistor. The schematics i have says to use a 2SA1930 but i have the spare BD140 from the SCHA so i was going to use that as its only limiting the inrush current (is that right). But looking at the tracks on the board it looks like the collector and emitter are in the wrong spots (the collector is the middle pin incoming power and emitter is outgoing power, right?) Cheers, Richard. they are you would have noticed that in the other SC HA's the 2SA1930/2SB5171 are rotated 180 deg compared to the BD139/140's The BD 139/140 wil be fine as current limiters orientated the right way round Robert
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Post by rbrook on Apr 6, 2009 13:56:30 GMT
Am i right in thinking that the supply power goes to the collector and then the emitter releases the power depending on how much voltage is put onto the base?
Richard.
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Post by Deleted on Apr 6, 2009 21:12:44 GMT
Am i right in thinking that the supply power goes to the collector and then the emitter releases the power depending on how much voltage is put onto the base? Richard. Richard Depending on the maximum current set by the choice of emitter resistor value, the base current will normally keep the CL transistor in a saturated condition. i.e. it will have minimum voltage drop between emitter and collector. The supply power goes to the emitter, and the device being powered becomes the collector load. The Toshiba devices not only have higher current ratings, and higher permissable dissipation, but they typically require less base current to keep them in saturation. As the inrush current on switchon is so large, the higher rated Toshiba devices are recommended for longevity reasons, AND they also sound better in this application. Alex
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Post by Deleted on Jul 24, 2009 1:02:47 GMT
An aquaintance was distracted by my SCHA strewen across my desk, open plan styley. (he was meant to be looking at my main amp prob). He was pretty impressed with the Grottos work!
He had a question, has anyone tried 2SA1145 and 2SC2705 in place of the BC560 & 550 s in the JLH ? Though not an audio-guy he said they can be better in certain cases.
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Post by Deleted on Jul 24, 2009 1:21:50 GMT
An aquaintance was distracted by my SCHA strewen across my desk, open plan styley. (he was meant to be looking at my main amp prob). He was pretty impressed with the Grottos work! He had a question, has anyone tried 2SA1145 and 2SC2705 in place of the BC560 & 550 s in the JLH ? Though not an audio-guy he said they can be better in certain cases. Chris John Linsley Hood specified devices with a "C" for their high gain. The 2 devices quoted have HFE of only 80 to 240 , so would be unsuitable for best results in this application. Alex
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Post by Deleted on Jul 25, 2009 13:34:37 GMT
Ah yes, I forgot/was unable to give him the reason for the choice at the time.
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