Phonoclone 3 - Page 4 - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 27th November 2008, 03:23 PM   #31
diyAudio Member
 
d to the g's Avatar
 
Join Date: Aug 2006
Location: minimalopolis
Quote:
Originally posted by Werner


@d to the g

You'll have to download and install Eagle www.cadsoftusa.com to view and manipulate the files. You may need the latest version, 5.3, I'm not sure.
When I say I'm trying it was more in reply to trying to follow, not trying to d/l the files. This circuit stuff doesn't come at all naturally to me.
  Reply With Quote
Old 28th November 2008, 05:40 AM   #32
rjm is online now rjm  Japan
Richard Murdey
diyAudio Member
 
rjm's Avatar
 
Join Date: May 2004
Location: Kyoto
Blog Entries: 103
I wondered at the time if I had miss-interpreted your post...

I don't think reading schematics comes naturally to anyone. Like reading sheet music, it takes practice. Plus there are some shorthand notation being used in the Eagle files here that are probably not intuitively obvious.

I'll take a stab at running though the Xreg circuit:

The raw voltage comes in at V-IN and V+IN. There is a filter capacitor C1/C1A that together with the total current draw of the load+regulator circuit elements, defines the initial ripple voltage.

The filtered voltage connects through the V++ and V-- "wormholes" to the collectors of the pass transistors Q1 and Q2.

The op amps are connected through the V+ and V- "wormholes" back to the main voltage filtered by the RC stage R6/6A and C2/2A. The op-amp power pins see about 10 times less ripple, and much less high freqency noise than the pass transistor.

The voltage powering the op amp is filtered and reduced by a two stage RCRC filter, R5/5A,R6/6A and C3/3A,C4/4A to generate the reference voltage. Its not an absolute reference, but the time constant is less than 1 Hz so it varies very slowly, essentially remaining "quiet" over the audio bandwidth and beyond.

The voltage amplifier is a textbook inverting configuration, but with the pass transistor inserted into the feedback loop. The output voltage is equal to the reference voltage multiplied by the gain, set as -R2/R1 and -R2A/R1A.

There are only a few oddities compared to your typical voltage regulator:

-The op amp is powered from split supply rails.

-The op amp is configured as an inverting amplifier, and takes the reference voltage generated from the opposite voltage rail as the one it regulates.

-The reference voltage is a fraction of the input voltage V+IN V-IN, not an absolute value because a filtered voltage divider provides a reference voltage, rather than a zener diode or precision reference.

The way the circuit "works" is as follows: the output is going to be equal to the reference voltage times the gain. For an 18 V input the op amp input sees about 450 mV at the input, 450 mV which is almost completely free of noise and ripple, and multiples that by -33 (R2/2A is 33k remember) to give -15 V, or 15 V from -450 mV for the positive rail.

The circuit is going to try to hold that 15 V constant no matter what the load does, over the bandwidth the circuit operates - in this case about 250 kHz - within the limit of the max current the transistor+raw voltage input can provide.
  Reply With Quote
Old 30th November 2008, 02:12 PM   #33
diyAudio Member
 
d to the g's Avatar
 
Join Date: Aug 2006
Location: minimalopolis
now that i get (for the most part). looking forward to hearing more about the performance.
  Reply With Quote
Old 1st December 2008, 05:13 AM   #34
diyAudio Member
 
johnsonlam's Avatar
 
Join Date: Nov 2008
Thanks RJM!

Will you update the Phonoclone in your homepage?

I've just changed to "Benz Micro MC Gold" and start to build Phonoclone, since I'm not very familiar in electronics, can I ask a simple question?

What resistor control the gain, and what's the "safe" value should I use? Since VSPS, my M-Audio Firewire Audiophile got clipping all the time (with VSPS default) and I need to lower the input.

Thank you for sharing your work with us, arigatou.
  Reply With Quote
Old 3rd December 2008, 05:47 AM   #35
rjm is online now rjm  Japan
Richard Murdey
diyAudio Member
 
rjm's Avatar
 
Join Date: May 2004
Location: Kyoto
Blog Entries: 103
Quote:
Originally posted by johnsonlam
What resistor control the gain, and what's the "safe" value should I use?
The basic phonoclone circuit is unchanged from before, so all the information regarding how to set the gain can be found on the existing Phonoclone page.

To reduce the gain change R2 from 1.5k to some lower value between 500 ohms and 1.5k.

/R
  Reply With Quote
Old 3rd December 2008, 10:27 AM   #36
diyAudio Member
 
johnsonlam's Avatar
 
Join Date: Nov 2008
Quote:
Originally posted by rjm
To reduce the gain change R2 from 1.5k to some lower value between 500 ohms and 1.5k.
/R [/B]
Thanks rjm.

Sorry I'm totally nuts to mathematics and I don't know how to calculate (please forgive my stipidity).

I guess there're people like me, maybe you can change the phonoclone's R2 description to the quote above, to make it more clear.

Thanks again.
  Reply With Quote
Old 3rd December 2008, 10:27 AM   #37
diyAudio Member
 
johnsonlam's Avatar
 
Join Date: Nov 2008
Hi rjm,

How to order the PCB of phonoclone?

Thanks.
  Reply With Quote
Old 6th December 2008, 07:21 AM   #38
rjm is online now rjm  Japan
Richard Murdey
diyAudio Member
 
rjm's Avatar
 
Join Date: May 2004
Location: Kyoto
Blog Entries: 103
There's that button next to all my posts, it says "email". You click on it, and send me a message to the effect that you want a set...
  Reply With Quote
Old 8th December 2008, 12:02 PM   #39
rjm is online now rjm  Japan
Richard Murdey
diyAudio Member
 
rjm's Avatar
 
Join Date: May 2004
Location: Kyoto
Blog Entries: 103
All beta boards are now spoken for.
  Reply With Quote
Old 9th December 2008, 01:50 AM   #40
rjm is online now rjm  Japan
Richard Murdey
diyAudio Member
 
rjm's Avatar
 
Join Date: May 2004
Location: Kyoto
Blog Entries: 103
It's easy to order your own from Olimex though. Just complete the following form and mail it to fastpcb@olimex.com. You don't need to send any Eagle files, the "as Purchase Order RM271108" part below tells them to use the working files they made for my order instead. "1 pc" below gets you two boards, one for each channel. If you want extra sets, edit it to 2 pcs, 3 pcs etc...

*****

1. Name:


(your name)


2. Company:


none


3. Billing address:


(address)


4. Shipping address:


(address)


5. Shipping option:


airmail


6. Order:


1 pc "DSS (Phonoclone_30n_final.brd x2)" as per Purchase Order RM271108
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB phonoclone boards c.d.s. Swap Meet 1 8th June 2008 09:04 PM
My take on the phonoclone Onvinyl Analogue Source 34 27th March 2007 02:11 PM
WTB: Phonoclone boards KT Swap Meet 0 20th February 2007 06:48 AM
Phonoclone Update rjm Analogue Source 70 6th July 2005 01:42 AM


New To Site? Need Help?

All times are GMT. The time now is 06:17 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2