leo
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Post by leo on Mar 11, 2010 14:57:30 GMT
Nice one! those look bob on
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Post by jeffc on Mar 12, 2010 5:28:43 GMT
Seems to be quite distinct species of these Crickets ;D A quick Google of Cricket Taxonomy brought up these.  Subfamily (or family) - Common Name Gryllinae - field cricket Gryllotalpidae - mole cricket Eneopterinae - bush cricket Mogoplistinae - scaly cricket Myrmecophilinae - ant cricket Nemobiinae - ground cricket Oecanthinae - tree cricket Pentacentrinae - anomalous cricket Trigonidiinae - sword-tail cricket Grottorockidae - audio cricket Nice PCB Alex, have it slotted in supplying the DIR9001 or DAC or both? ;D cheers.. jeffc |
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Post by Deleted on Mar 12, 2010 5:58:13 GMT
HI Jeff
It isn't slotted in yet. Just tested O.K. I still have some time left for the added JLH on the +5V rail to fully stabilise, before changing anything else.
It will replace the existing Cricket feeding 3.3V to the DAC, as well as feeding a cleaner 3.3V to the DIR9001.
Have you tried 22uFs as per the originals in that area yet ?
Alex
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Post by jeffc on Mar 12, 2010 7:18:46 GMT
Not yet, bass is still good and possibly not as affected as initially thought, so no urgency on that front. And a 5V Cricket supply to the DAC will have to wait for a Mr Fixit job on my soldering station and until I get back from Bangladesh. Busy as all heck getting everything together for the trip right now.
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Post by Deleted on Mar 12, 2010 18:11:27 GMT
Something just rolled up....  All I need now is some free time to get started! |
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Will
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Post by Will on Mar 12, 2010 18:47:43 GMT
Good Stuff Chris! I very nearly got time to apply power to mine this week.
Jeff and Alex, your crickets are looking good, and I'm looking forward to hearing how good it sounds, especially the JLH on the 5V rail.
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leo
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Post by leo on Mar 12, 2010 20:30:57 GMT
MUST RESIST! that picture is giving me real itchy fingers  |
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Post by Deleted on Mar 12, 2010 20:44:36 GMT
Good Stuff Chris! I very nearly got time to apply power to mine this week. Jeff and Alex, your crickets are looking good, and I'm looking forward to hearing how good it sounds, especially the JLH on the 5V rail. Will I think there is a further small improvement with the JLH on the +5V rail to the Input PCB. However, since starting the DAC, my hearing has also improved because of a 50 point drop in BP, which is the lowest it has been for several years. I may try fitting the dual Cricket in the next day or 2. This will mean removing the 5V to 3.3V Regulator and the diode at it's output. It is so revealing now, that just placing a piece of vinyl sound proofing material as used on inner car doors etc, under the Oppo which was only being used as a Transport, made a marked improvement to the low end and midrange,but the stereo image was no longer quite as far forward. No Frans, I didn't imagine it either !!! Alex |
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Post by Deleted on Mar 12, 2010 22:31:23 GMT
Something just rolled up.... All I need now is some free time to get started! Hi Chris Did you try and get 4 x 2n2 polyprops and 2 x 100pF polyprop or polystyrene while you were waiting for the kit ? I would recommend that you go directly to the simplified filter circuit as per the schematic and photo that I posted. Alfred, Jeff and myself all agree that it sounds quite a bit better.You could always use 4 x normal 2n2 and 2 x100pf ceramic while you are sourcing 2n2 polypropylene and 100pf capacitors. The few different metal film resistors should be more readily available. Alex |
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Post by Deleted on Mar 13, 2010 12:03:30 GMT
Alex,
I've only just read through the Jaycar notes. (mine has that missing track link too)
I think first port of call is to read through this thread again, to remind myself of the extra bits I'll need, then I'll start ordering and hopefully obtain the necessary, so far, in one round of orders.
Ta,
Chris
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Post by Deleted on Mar 13, 2010 20:55:16 GMT
Alex, I've only just read through the Jaycar notes. (mine has that missing track link too) I think first port of call is to read through this thread again, to remind myself of the extra bits I'll need, then I'll start ordering and hopefully obtain the necessary, so far, in one round of orders. Ta, Chris Chris Don't forget that it is very disappointing without at least a JLH for the +-15V supply to the Output PCB. Alex |
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Post by Deleted on Mar 14, 2010 5:26:35 GMT
UPDATE.
I have now connected the 2nd half of the dual 3.3V Cricket to the 3.3V rail for the DIR9001. This entailed removing the 3.3V regulator and diode D14.
I doubt that I can give a clearer indication about the improvement that this has made, than that which JeffC said to me.
To quote Jeff :
Next step after a few days of listening confirmation, will be doing similar to the DAC PCB. i.e. Supplying the 5V to the DAC via a 5V reference Cricket.This will involve removing the 7805 and D15
Alex
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pagan
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Post by pagan on Mar 15, 2010 8:25:06 GMT
It's been a while.......
Has anyone questioned the lenght of the I2S data cable?
From my experience, I try to keep them as short as possible.
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Post by Deleted on Mar 15, 2010 8:53:36 GMT
It's been a while....... Has anyone questioned the lenght of the I2S data cable? From my experience, I try to keep them as short as possible. Allan As you say, I2S was designed for direct connection between I.C.s. However, there are now available high quality screened I2S cables in much longer lengths. Alex www.revelationaudiolabs.com/cables-digital/index.htm#i2s |
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pagan
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Post by pagan on Mar 15, 2010 11:15:31 GMT
Alex
interesting.....
now there's a question for the cable thread.
I do notice that the cable is not very long.
Allan
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Post by Deleted on Mar 15, 2010 20:26:24 GMT
Alex interesting..... now there's a question for the cable thread. I do notice that the cable is not very long. Allan Allan My understanding is that it is a bandwidth related issue. Provided the lengths are kept exactly the same, and they are very well screened, the working distance can be extended , but at the expense of bandwidth due to increased capacitance.The measures suggested elsewhere by Robert should be able to extend the working distance as long as the buffers were VERY close to the source. Anyway, that is my take on it FWIW. Alex P.S. I saw a TI development kit, where they supplied premade 16 wire IDC cables.They didn't state the length of the cables supplied. |
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Post by pagan on Mar 16, 2010 11:21:06 GMT
Alex interesting..... now there's a question for the cable thread. I do notice that the cable is not very long. Allan hehe get to quote myself.... "cable not very long" hmmm 0.5 meter or 1 meter... There are some devices out the with I2S inputs/outputs but they will have drivers/buffers of some kind for the task. These are what these cables are pushed too. Alex "My understanding is that it is a bandwidth related issue." It's more to to with a timing issue" yes the old "j" word. One question........... would you connect a clock the same way? Allan |
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Post by Deleted on Mar 16, 2010 20:16:23 GMT
Alex interesting..... now there's a question for the cable thread. I do notice that the cable is not very long. Allan hehe get to quote myself.... "cable not very long" hmmm 0.5 meter or 1 meter... There are some devices out the with I2S inputs/outputs but they will have drivers/buffers of some kind for the task. These are what these cables are pushed too. Alex "My understanding is that it is a bandwidth related issue." It's more to to with a timing issue" yes the old "j" word. One question........... would you connect a clock the same way? Allan Allan No, it's a bandwidth issue, if the cable is well screened,but not further buffered. Yes, Jitter becomes a major problem with extended length if extreme care isn't taken with screening,terminations etc. I "Googled" this subject quite extensively, and the manufacturer quoted in the earlier link is only one of several manufacturers. Alex |
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Post by Deleted on Mar 16, 2010 20:28:37 GMT
UNEXPECTED RESULT.
Yesterday morning I removed the onboard 7805 regulator that supplies the DAC via the regulated +15V rail, and fed this area via a 5V "Cricket".
The sound became more diffused again, and the soundstage receded quite a bit. The original +5V supply to the DAC was derived from the +15V rail via the JLH, so other than a little noise from the 7805 itself, would have been a fairly quiet low impedance supply.
I found a genuine Motorola 5V regulator in my stash, so I will try it instead of the generic type 7805 supplied with the kit.
Alex
P.S.
Out of curiosity, I connected the DAC 5V supply to the 5V from the JLH via a longer than desireable pair of twisted leads. The sound was then very much like it was before trying the "Cricket" at that location.
I will leave it like that for an extended listening session. I suspect that the 5V supply to the DAC needs to be not only very low noise, but also very low impedance for better than average results. The 3.3V "Crickets" are however very worthwhile when supplying 3.3V to both the DIR9001 and the 3.3V supply to the DAC.
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Post by Deleted on Mar 17, 2010 4:10:45 GMT
UPDATE.
I have now had a chance to have an extended listen. Much of the ultra detail has gone with the 5V from the JLH now supplying the 5V to the DAC chip, but the sound is now more "full bodied" with an incredibly good LF extension with DTV audio! It's rather like the JLH did for the SC HA.
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Post by Deleted on Mar 23, 2010 4:28:18 GMT
UPDATE. Now with JLH PCBs designed by Greg Erskine, and commercially made for Greg as a small pilot run. Greg gave me a few to try out, and this was greatly appreciated. Greg is presently further refining this design. They certainly look better than my home brew JLHs, ;D and the use of the screw terminal strips makes an additional connection much easier.  They do of course sound virtually identical to what I was previously using. I chose to use different MKT capacitors in the version with 2 x dual +VE outputs, which has an output of +5V. Half of this other +VE version JLH has been left for future experimentation with this DAC.The one using the red Wima 2.2uF capacitors is a normal dual polarity JLH working at +-15V. Alex  The in situ photo does not do this PCB justice, so I have attached a photo taken before installation of the dual polarity JLH. URL=http://img511.imageshack.us/i/jlh1gregerskine.jpg/]  [/URL] |
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Will
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Post by Will on Mar 23, 2010 8:32:37 GMT
Greg's JLH boards look very, very nice indeed.  How are you finding this dac now you've modded it, compared to your x-dac? |
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FritzS
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Post by FritzS on Mar 23, 2010 8:34:56 GMT
UPDATE. Now with JLH PCBs designed by Greg Erskine, and commercially made for Greg as a small pilot run. Greg gave me a few to try out, and this was greatly appreciated. Greg is presently further refining this design. They certainly look better than my home brew JLHs, ;D and the use of the screw terminal strips makes an additional connection much easier. They do of course sound virtually identical to what I was previously using. I chose to use different MKT capacitors in the version with 2 x dual +VE outputs, which has an output of +5V. Half of this other +VE version JLH has been left for future experimentation with this DAC.The one using the red Wima 2.2uF capacitors is a normal dual polarity JLH working at +-15V. Alex The in situ photo does not do this PCB justice, so I have attached a photo taken before installation of the dual polarity JLH. URL=http://img511.imageshack.us/i/jlh1gregerskine.jpg/] [/URL][/quote] Alex, congratulation - looks very nice and professional  Gives the commercial PCB's for other RockGrotto members too? I search for Class-A HA commercial PCB's too. |
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Post by Deleted on Mar 23, 2010 9:00:22 GMT
Greg's JLH boards look very, very nice indeed. How are you finding this dac now you've modded it, compared to your x-dac? Hi Will Greg is redesigning the JLH for a few small changes, mainly to labelling, a little extra space between the 2SA1930s and the main electros. He will also be altering the CL transistor type from the BC639/BC640 to the 2SA1930 and 2SC5171, which will mean a minor change to their copper pads. I much prefer the sound now with the 5V JLH supplying +5V to the DAC. The sound stage isn't so huge as with the 7805 there in combination with the 2 x 3.3V Crickets, but the sound is fuller sounding, and with a low end ambience/reverb to die for when it is there in better than average productions on TV. It just fills the air in front of you. Some of the USA soapies have very good LF effects, surprisingly ! I haven't yet compared the X-DAC V3 with the SC DAC in the main system, as I do not believe it is necessary. I have recently ordered a 1PPM 24.576MHZ 5V TXCO via ebay, if that gives you a clue ? Friedrich Will and Jon MAY be getting some JLHs made for supply via RG for the members. There will not be any commercial PCBs made for the Class A. Will has created special artwork for them to be made by members who are able to make their own PCBs.Will's version does not require any modifications to be made. Alex |
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Will
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Post by Will on Mar 23, 2010 9:09:21 GMT
Hi Alex,
Thanks for your impressions, now that you've had time to have a proper listen, and lived with it a while. Interesting you mention LF effects, as a years ago I was at a friends house who had a very nice surround sound setup. He was doing a demo of what it could do, and put a Star Trek:TNG dvd on, and selected an engine room scene. The deep, thrumming 'whum, whum' sound of the engine was very impressive, and something that you would miss completely on a normal TV setup.
Friedrich, are you having problems with the set of class A boards I sent you? (The first set made) The only thing not implemented in them is the LTP mod, which is straightforward, and I can help if you wish. The newer designs do incorporate the LTP mod.
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