Greg3333 said:
Greg,
Assuming the secundary winding of the tranny 5 ohm, a load of 10mA results in a ripple of 60mV with 470uF caps. With 940uF only 15mV.
The regulator will reduce ripple further and a small cap on the opamp (100uF) will wipe out ripple to almost zero. Use for this 100uF one with good HF response (BG).
Ripple on your power rails interferes with music, very faint but noticeable.
Regards, Jaap
Re: Re: Re: Re: Grounding a system can be quite amusing
No, I don't have the equipment to do that. I have an earth rod hammered into the ground and it sounds best after rain
I'm about to move house so it's another set of challenges coming up, including where to stick the next earth rod, and how best to interfere with the mains without killing myself or it being obvious (rented house).
Simon
avr300 said:
No, I don't have the equipment to do that. I have an earth rod hammered into the ground and it sounds best after rain
I'm about to move house so it's another set of challenges coming up, including where to stick the next earth rod, and how best to interfere with the mains without killing myself or it being obvious (rented house).
Simon
Sorry to ask such basic questions in this post but I'm terrible at speccing components. 
I figured I might as well order a few more parts from Rapid while I was ordering the 12V PS parts.
Are the SB330 Schottky diodes also suitable for D801-4 and D811, D812?
Is there much improvement to sound quality from adding a filtered IEC socket in place of the original power lead? How about this cheap type?
How about a varistor across the power inlet? 20N391K?
I'll have to order opamps (probably go for OPA2134 until I can afford to go down the Browndog and 627 route), maybe new regulators and fancy caps elsewhere.
Does this sound like a reasonable upgrade path? I'm looking forward to hearing the player with slightly better opamps then I'll probably do the Acoustica clock hack once I've figured out what parts I need to order for that one.
Thanks for your help. I've read a lot of this thread now but the huge amount of information's a bit overwhelming so I apologise for inevitably repeating questions that have already been asked somewhere in the 367 pages!
Greg
I figured I might as well order a few more parts from Rapid while I was ordering the 12V PS parts.
Are the SB330 Schottky diodes also suitable for D801-4 and D811, D812?
Is there much improvement to sound quality from adding a filtered IEC socket in place of the original power lead? How about this cheap type?
How about a varistor across the power inlet? 20N391K?
I'll have to order opamps (probably go for OPA2134 until I can afford to go down the Browndog and 627 route), maybe new regulators and fancy caps elsewhere.
Does this sound like a reasonable upgrade path? I'm looking forward to hearing the player with slightly better opamps then I'll probably do the Acoustica clock hack once I've figured out what parts I need to order for that one.
Thanks for your help. I've read a lot of this thread now but the huge amount of information's a bit overwhelming so I apologise for inevitably repeating questions that have already been asked somewhere in the 367 pages!
Greg
Greg3333 said:Sorry to ask such basic questions in this post but I'm terrible at speccing components.
I figured I might as well order a few more parts from Rapid while I was ordering the 12V PS parts.
Are the SB330 Schottky diodes also suitable for D801-4 and D811, D812?
Looks fine to me, I've used 100V/1A ratings. You might aswell replace all the power supply diodes as the inferior types radiate noise into the player.
Probably not much, no, but then the price is small. Alternatively a good sized X-rated (safety rating for across the mains) capacitor will do some good for it. The main reason to use a socket is to try a different power cable and have the convenience of detaching it easily.
Well you could but bear in mind they can 'wear out' and are perhaps detrimental to sound quality (some have said). An isolation transformer works wonders though! Search Ebay for "site transformer" or "isolation transformer". There's nothing good right now, but you can get lucky and buy an "untested" 500va rated 240 to 240v job for not much money. Don't pay more than £20 or so.
2134 is a lovely op-amp. 627 is better but not quite in line with the price difference, and more complicated to install.
Yeh, I reckon so!
Regards,
Simon
Hello Gents,
I've been following this thread and have read/skimmed my way to page 95 so far. I'm hoping the updated mod list from Brent is coming up soon.
I have two questions.
1) I own a Decware Z-Box which is effectively a Cathode Follower. It helps to smooth the sound and to my ears provide a bit more 3D in the soundstage. If I was to upgrade the Op Amp, do you think I would hear a significant improvement?
2) Have you guys heard about Burson Audio from Australia. They have a few DIY solutions, probably after you own hearts. Have any of you used any of their gear?
Simon (from Australia, the existing one is much better looking)
I've been following this thread and have read/skimmed my way to page 95 so far. I'm hoping the updated mod list from Brent is coming up soon.
I have two questions.
1) I own a Decware Z-Box which is effectively a Cathode Follower. It helps to smooth the sound and to my ears provide a bit more 3D in the soundstage. If I was to upgrade the Op Amp, do you think I would hear a significant improvement?
2) Have you guys heard about Burson Audio from Australia. They have a few DIY solutions, probably after you own hearts. Have any of you used any of their gear?
Simon (from Australia, the existing one is much better looking)
YoungSC said:
Hi Simon, welcome and enjoy the pages!
To put it frankly, the quality of music reproduction never betters from another amplification step. Be it tube amplified, FET, transistor or IC.
If the source audio signal has imperfections it can't be taken away electronically without paying a price. This holds for noice, hum, dynamics.
Holistic (3-D) reproduction suffers most from lack of micro details. Due to losses in capacitors, stray fields around components and applied feedback not all details in the recording are leaving the speakers as intended. As extra handicap the CDP suffers from glitches in the time domain because of digital jitter.
In the second place both channels have to have identical characteristics (amplification, bandwith). Much is gained in the CDP by matching components to a high level of exactness by using 1% tolerance or individual matching with a DMM.
Lastly (to a lower extent) the rest of your hifi gear must be of high quality to hear all your modded CDP has to offer.
For starters you might begin with building a new 12V supply to your existing opamps. This should not cost the world and is a considered a major step up the reproduction stairs. See the pages from last weeks for details.
Regards, Jaap
Re: Re: Re: Re: Re: Grounding a system can be quite amusing
Yes !
I have the real earth connected via my mains to my CDP and pre. Why should I insert a choke ? Haven't measured the impedance of the common mode choke. I will.
0 between CDP and PRE (they are on same earth) Can't remember the DC to the power.
What is VDE wire ?
Sorry for not answering earlier. I thought my CDP died yesteday - started to spin the disc like mad. Tracked it down to instability due to components mounted in sockets on my Flea board. Soldered the AD797 and the TenT XO directly onto the PCB and it behaves nicely again.
disco said:
Yes !
I have the real earth connected via my mains to my CDP and pre. Why should I insert a choke ? Haven't measured the impedance of the common mode choke. I will.
0 between CDP and PRE (they are on same earth) Can't remember the DC to the power.
What is VDE wire ?
Sorry for not answering earlier. I thought my CDP died yesteday - started to spin the disc like mad. Tracked it down to instability due to components mounted in sockets on my Flea board. Soldered the AD797 and the TenT XO directly onto the PCB and it behaves nicely again.
Re: Re: Re: Re: Re: Re: Grounding a system can be quite amusing
I presume this ground is separated from the rest of the house?
Regards, Jaap
The choke should filter RF before ground is applied to the device. It's just hypothetical.avr300 said:
I presume this ground is separated from the rest of the house?
I mean the DC between cabinet and ground, when the devices are not connected to ground.
Don't know the exact meaning of the letters but it's common installation wire, going to light bulbs etc.
Use them 'drilled' sockets, not the cheap ones
Regards, Jaap
Re: Re: Re: Re: Re: Re: Re: Grounding a system can be quite amusing
Your right. No need to filter this.
I guessed that. I'll measure.
Yellow/green (at least in DK it is). Yes, it is 2.5sq-mm going from the rod to my dedicated mains out plug. Then it's 1.5sq-mm mains kabel (nothing fancy here!) and internal in the CDP and PRE I guess it's .75sq-mm.
Hey, no cheap .... here. I have used tulip sockets - best quality - but despite that, the d... thing oscillated. Strange though, not from the beginnig, it started yesteday. Not that I haven't been warned, the Flea manual says nothing 'bout sockets but a whole lot about fast and unstabile OPAMPS.
disco said:
Your right. No need to filter this.
I guessed that. I'll measure.
Yellow/green (at least in DK it is). Yes, it is 2.5sq-mm going from the rod to my dedicated mains out plug. Then it's 1.5sq-mm mains kabel (nothing fancy here!) and internal in the CDP and PRE I guess it's .75sq-mm.
Use them 'drilled' sockets, not the cheap ones
Regards, Jaap [/B]
Hey, no cheap .... here
. I have used tulip sockets - best quality - but despite that, the d... thing oscillated. Strange though, not from the beginnig, it started yesteday. Not that I haven't been warned, the Flea manual says nothing 'bout sockets but a whole lot about fast and unstabile OPAMPS.
Re: Re: Re: Re: Re: Re: Re: Re: Grounding a system can be quite amusing
The gain of the error amplifier falls with frequency, so does the amount of gain available for reducing output impedance. As a result the output impedance rises with frequency. A shunt capacitor (33-100uF) shortly mounted at the output of the Flea regulator maintains a low output impedance at high frequencies. Don't know if it is already implemented.
Regards, Jaap
I don't recall the Flea circuit but maybe this thought can be of help.avr300 said:I have used tulip sockets - best quality - but despite that, the d... thing oscillated. Strange though, not from the beginnig, it started yesteday. Not that I haven't been warned, the Flea manual says nothing 'bout sockets but a whole lot about fast and unstabile OPAMPS.
The gain of the error amplifier falls with frequency, so does the amount of gain available for reducing output impedance. As a result the output impedance rises with frequency. A shunt capacitor (33-100uF) shortly mounted at the output of the Flea regulator maintains a low output impedance at high frequencies. Don't know if it is already implemented.
Regards, Jaap
Sockets are absolutely not recommended with the AD797; if you must have one, then put the bypass cap across the pins of the opamp, not on the board, or the extra inductance will make oscillation very likely. Hence the note on p.18 of the manual 'The use of sockets for the op-amp is to be discouraged for stability reasons, especially with the AD797'
There is an output cap on the flea (10uF min) to guarentee stability. It does very little at the circuits operating frequency of interest (i.e clock freq.) though.
There is an output cap on the flea (10uF min) to guarentee stability. It does very little at the circuits operating frequency of interest (i.e clock freq.) though.
Just to close this OT.
My earth is 60 ohm measured with one of these guys:
http://www.kew-ltd.co.jp/en/products/earth/4102A.html
My earth is 60 ohm measured with one of these guys:
http://www.kew-ltd.co.jp/en/products/earth/4102A.html