One other anomaly I want to pose - I installed a new clock on the dsp board and there is no perceptible change in the sound that I can hear. I expected big improvement in sound based on the fact that the existing circuit uses 2 clocks & 3.3V off the board
What am I doing wrong or am I ?
I know the trace feeding pin 30 of the DIR is long & convoluted but this was all I could connect to & this is where others before me have connected to! Others seem to have reported significant sonic improvement in a clock change. Is the Crystek part not up to par?
- I removed R1049 resistor (circled on attached schematic) and connected the clock output to the track that goes to pin 30 od DIR (AK4114 chip)
- my clock PS cicuit is shown in attachment also and it takes it's 5V feed from the board but regulates it down to 3.3V
- I'm using a Crystek CS33 osc - datasheet also in attachment
Link to datsheets & schematic http://www.4shared.com/dir/6662634/a4102ae7/Jocko.html
What am I doing wrong or am I ?
I know the trace feeding pin 30 of the DIR is long & convoluted but this was all I could connect to & this is where others before me have connected to! Others seem to have reported significant sonic improvement in a clock change. Is the Crystek part not up to par?
- I removed R1049 resistor (circled on attached schematic) and connected the clock output to the track that goes to pin 30 od DIR (AK4114 chip)
- my clock PS cicuit is shown in attachment also and it takes it's 5V feed from the board but regulates it down to 3.3V
- I'm using a Crystek CS33 osc - datasheet also in attachment
Link to datsheets & schematic http://www.4shared.com/dir/6662634/a4102ae7/Jocko.html
Jkeny.
I run 8*470 BG-N. Perhaps I should try an Aerovox. You never know if there is a better solution out there.
Though I think it'll depend on several factors how it finally works.
With my 100db/SPL system I do not draw very much current.
This for sure will have an impact. My battery is quite good already.
Actually the biggest change which came with the battery change,
were the added dynamics.
However I'll give the Aerovox a try.
I need a perfect base for my TAS5706 project.
I'll skip the detour over Panasonic
I run 8*470 BG-N. Perhaps I should try an Aerovox. You never know if there is a better solution out there.
Though I think it'll depend on several factors how it finally works.
With my 100db/SPL system I do not draw very much current.
This for sure will have an impact. My battery is quite good already.
Actually the biggest change which came with the battery change,
were the added dynamics.
However I'll give the Aerovox a try.
I need a perfect base for my TAS5706 project.
I'll skip the detour over Panasonic
Correction Soundcheck,
The cap is actually a BHC ALP22a - part of the RS range of products - has been mentioned on DIYA - considered nothing special but works wonderfully in this position
http://radionics.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2271169
I'm using the 40V version esr of 50 mohm & impedance of 45 mohm with a ripple current handling of 4.5 Amps.
I know I should be using a higher volt rated cap with even better specs - these were just what was at hand!
Are U building the TAS5706 using Koon's board?
The cap is actually a BHC ALP22a - part of the RS range of products - has been mentioned on DIYA - considered nothing special but works wonderfully in this position
http://radionics.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2271169
I'm using the 40V version esr of 50 mohm & impedance of 45 mohm with a ripple current handling of 4.5 Amps.
I know I should be using a higher volt rated cap with even better specs - these were just what was at hand!
Are U building the TAS5706 using Koon's board?
I'm looking to connect I2S into this XR57 amp - I've seen another thread here doing the same for XR55 but he connected after the DSP chip & had vol control & clipping issues -
My best bet is to connect to I2S lines going into the DSP Yamaha chip - these are fed from a logic chip, a LC245A Octal Bus transceiver. This chip gets fed ftrom the outputs of the A/D ICs (3) & from the DIR IC AK4114
If I connect I2S to the A side of this chip are the upstream ICs (Ak4114 & A/Ds) safe from being destroyed by the I2S signal?
Schematic attached
My best bet is to connect to I2S lines going into the DSP Yamaha chip - these are fed from a logic chip, a LC245A Octal Bus transceiver. This chip gets fed ftrom the outputs of the A/D ICs (3) & from the DIR IC AK4114
If I connect I2S to the A side of this chip are the upstream ICs (Ak4114 & A/Ds) safe from being destroyed by the I2S signal?
Schematic attached
Where is the earliest in the signal chain that you can splice into I2S ie. does the DIR chip (AK4114) have I2S coming into it or out from it? I've looked at the datasheet (Pg 29) & the XR57 DSP schematic (Pg 71) - There are different modes controlled by pins 3,5 & 7. Both pin 5 & 7 are held low according to the schematic & pin 3 is dependent on HDMI_SPDIF signal. So it seemsit can be set for only mode 0 or 1 - 24 bit LJ in & 16 or 18 bit RJ out!
When it gets to the Yamaha chip, the micro P controls registers which determine the input/output formats. These register settings are unknown to me!
It would seem the only I2S splice available is after the Yamaha IC which gives brings up the issue Pawelp had, namely Volume control (not too much of a problem) & digital clipping because Front R&L were 10dB louder than rest of channels (big problem)!
IIt looks like I2S is a non-runner with this amp unless I've forgotten something?
When it gets to the Yamaha chip, the micro P controls registers which determine the input/output formats. These register settings are unknown to me!
It would seem the only I2S splice available is after the Yamaha IC which gives brings up the issue Pawelp had, namely Volume control (not too much of a problem) & digital clipping because Front R&L were 10dB louder than rest of channels (big problem)!
IIt looks like I2S is a non-runner with this amp unless I've forgotten something?
I have given up on I2S connection for the moment as it doesn't work for me - if others have succeeded I would be grateful to hear the details.
On another front - I have connected batteries into the main PS supply to generate the 15V, 5V, 3.3V, etc supplies and this sounds even better than the batteries just powering the output stage!
I did this by taking out the dual diode D711 that generates the main + supply and also is fed through to LB731 inductor & DC-DC section to generate 15, 5Volt supplies. I then connected the Battery + to C717 +
As I said this sounds great BUT I have to connect the AC supply for the other 3.3 & 5.7V supplies. So with the AC connected, the main switching IC (IC701) begins to oscillate (makes clicking noises) after about 10 mins & I have to turn off.
If I stop the AC supply going to IC701 by removing the main rectifier D701, I get a DC_Det error (F76).
Does anybody know how to overcome this? It seems to be generated by the main microprocessor IC6801 but I dont know how or why it's generated. I suspect the voltage detector IC702 but don't know how to stop it happening!
I think it's worthwhile to try this as the music I hear in the 10 mins of operation is cleaner/clearer than when the voltages are generated by the SMPS.
Any help?
On another front - I have connected batteries into the main PS supply to generate the 15V, 5V, 3.3V, etc supplies and this sounds even better than the batteries just powering the output stage!
I did this by taking out the dual diode D711 that generates the main + supply and also is fed through to LB731 inductor & DC-DC section to generate 15, 5Volt supplies. I then connected the Battery + to C717 +
As I said this sounds great BUT I have to connect the AC supply for the other 3.3 & 5.7V supplies. So with the AC connected, the main switching IC (IC701) begins to oscillate (makes clicking noises) after about 10 mins & I have to turn off.
If I stop the AC supply going to IC701 by removing the main rectifier D701, I get a DC_Det error (F76).
Does anybody know how to overcome this? It seems to be generated by the main microprocessor IC6801 but I dont know how or why it's generated. I suspect the voltage detector IC702 but don't know how to stop it happening!
I think it's worthwhile to try this as the music I hear in the 10 mins of operation is cleaner/clearer than when the voltages are generated by the SMPS.
Any help?
you need to find the signal line that tells the cpu that there is a problem. it will be marked POWER_GOOD or +V_DET or something like that. if it has a slash in front of it (like /+V_DET ) or has a line over it it means it's an active low. measure that line with the power supply operating normally from the AC line. if it's at +5v, you will need to tie it to a +5 rail through a 1k resistor. if it is low, tie it to ground through a 1k resistor. most likely it will be an active high signal, and the cpu will expect +5V on that line. it may be tied to the DC detect circuits through a diode. sometimes there are multiple uses for the protection inputs of the cpu. i know that pioneer uses the /OVLD pin on their cpu not only to detect a shorted speaker, but to also shut the amp down if there's a fault in either the -30V supply for the display or one of the supplies for the analog circuitry (like the +/-15V supplies). i've used the method of "fooling" the cpu to localize problems with the fault detection circuits.
Thanks Unlejed,
I did think of that - the DCDET line is active low and it's from pin 2 of the microprocessor - so I was worried that putting a +5.1V on it might damage the M/P as it's an ouput pin only.
Have you done this before - putting +V on an M/P output pin?
I guess the safest way would be to disconnect this pin somewhere along the pathway back to the M/P?
I did think of that - the DCDET line is active low and it's from pin 2 of the microprocessor - so I was worried that putting a +5.1V on it might damage the M/P as it's an ouput pin only.
Have you done this before - putting +V on an M/P output pin?
I guess the safest way would be to disconnect this pin somewhere along the pathway back to the M/P?
you want to trick the inputs to the cpu, not the outputs. if you tie the DCDET line high (or low as the case may be) you don't have any DC offset protection anymore. what you want is to find the specific transistor that senses the P/S rails and disable that specific transistor. that transistor will most likely be on the power supply board. there may even be more than one. if there's more than one, all of the collectors of the fault detection transistors will be "wired ORed" together, either through diodes or directly paralleled. they are fairly easy to spot, as they will be either SMT transistors or TO-92 devices
Thanks again uncle,
It's just you & me here!
I had a look at this system but realised that I'm missing some neg supplies that are needed for the FLourescent display & -15V for other parts of the circuit.
So I'm trying to find out how/where these are generated
I've attached schematic of the PS supply with the neg voltages circled.
I presume to the right of the trafo are the input voltages (FL_+4R6V & FL_0) & to the left the output voltages (-15, -VP). I just don't know where the FL neg voltages are generated?
It seems to be the same circuitry in all the models back to XR45 (that's as far back as I have)
Does anybody know where these are generated?
It's just you & me here!
I had a look at this system but realised that I'm missing some neg supplies that are needed for the FLourescent display & -15V for other parts of the circuit.
So I'm trying to find out how/where these are generated
I've attached schematic of the PS supply with the neg voltages circled.
I presume to the right of the trafo are the input voltages (FL_+4R6V & FL_0) & to the left the output voltages (-15, -VP). I just don't know where the FL neg voltages are generated?
It seems to be the same circuitry in all the models back to XR45 (that's as far back as I have)
Does anybody know where these are generated?
Ok, so where would I provide the neg DC supply, at -VP?
Here's some readings I took
-VP = -28V
T731 transformer
pin 15 = -31
pin 14 = -15
pin 2 = -25
pin 3 = -19
So am I right in thinking that these are all generated from -VP? What I want to do is provide one neg supply from which all the rest are generated!
Here's some readings I took
-VP = -28V
T731 transformer
pin 15 = -31
pin 14 = -15
pin 2 = -25
pin 3 = -19
So am I right in thinking that these are all generated from -VP? What I want to do is provide one neg supply from which all the rest are generated!
it should provide those voltages if you provide VDD which feeds the switcher that provides the -VP,+/-5, +/-15 rails. the other swither in the schematic, i'm not sure where it's power comes from, but it needs to be fed too (the power for VDD and the power for the other switcher are off the right side of the schematic you posted. it is possible to provide battery power to the whole unit if you pur 10 12V gel cells in series. the AC input gets directly rectified anyway through a bridge rectifier (polarity isn't important if you connect a 120V battery to the line plug). that would also solve your problem with the cpu registering a power supply fault.
Sorry about this long post:
Let me fill in the picture by including the rest of the PS schematic here with the main switcher circled in green which provides VDD (the red circle is the volume controlled voltage adjustment). This provides VDD (from 10 to 40V DC) to the switcher (on the page I attached before) which then gives +-5V, +-15V, -VP,etc.
I thought by providing 20VDC to this switcher it would generate the same set of voltages. But it didn't!.
As you can see if you look back at the first PS attachment VDD is a red line which comes in along the bottom of the schematic through an inductor (LB731) & then through a PWM controller & into the switcher. I fed my 20V DC from SLA battery into just before the inductor but no neg voltages.
When I looked closely at the schematic, I saw that the switcher seems split in two with this VDD going to the bottom half of it - pins 5,6,7 to give the pos voltages & some neg supply going to pins 2,3 at the top half giving the neg voltages (-5V, -15V, etc). I just couln't see where this neg supply was coming from - either on the schematic or on the pcb.
This is my dilemma - where does this neg supply come from & to which pin is it supplied? The schematic would seem to suggest pins 2 & 3 are the neg supply (FL_+4R6V and FL_0) but I can't find where they are generated. Is it to these pins on the switcher that I should feed my new neg DC in order to provide all the neg voltages needed by the amp? I didn't want to do this unless absolutely sure because I don't want to kill the amp with wrong voltages (polarity or value). So I'm looking to find the source of this neg supply
Am I being stupid or what am I missing?
PS. the other switcher on the first schematic is the power standby circuit which is always on when there is juice. The main VDD is switched on via relay when unit is taken out of standby
That's what I thought & where I originally started - I provided VDD to this switcher but didn't get the neg voltages?unclejed613 said:
Let me fill in the picture by including the rest of the PS schematic here with the main switcher circled in green which provides VDD (the red circle is the volume controlled voltage adjustment). This provides VDD (from 10 to 40V DC) to the switcher (on the page I attached before) which then gives +-5V, +-15V, -VP,etc.
I thought by providing 20VDC to this switcher it would generate the same set of voltages. But it didn't!.
As you can see if you look back at the first PS attachment VDD is a red line which comes in along the bottom of the schematic through an inductor (LB731) & then through a PWM controller & into the switcher. I fed my 20V DC from SLA battery into just before the inductor but no neg voltages.
When I looked closely at the schematic, I saw that the switcher seems split in two with this VDD going to the bottom half of it - pins 5,6,7 to give the pos voltages & some neg supply going to pins 2,3 at the top half giving the neg voltages (-5V, -15V, etc). I just couln't see where this neg supply was coming from - either on the schematic or on the pcb.
This is my dilemma - where does this neg supply come from & to which pin is it supplied? The schematic would seem to suggest pins 2 & 3 are the neg supply (FL_+4R6V and FL_0) but I can't find where they are generated. Is it to these pins on the switcher that I should feed my new neg DC in order to provide all the neg voltages needed by the amp? I didn't want to do this unless absolutely sure because I don't want to kill the amp with wrong voltages (polarity or value). So I'm looking to find the source of this neg supply
Am I being stupid or what am I missing?
PS. the other switcher on the first schematic is the power standby circuit which is always on when there is juice. The main VDD is switched on via relay when unit is taken out of standby
ok, here's your problem. T721 and IC721 are your standby voltage supply. this provides the idle voltage for the cpu. unless the cpu goes through the power up sequence, turning on the other switchers, nothing's going to happen. for the other switchers to work, the cpu needs to turn them on. on each transformer, there's only one input winding, the one connected to the switcher chip or transistor connected to the chip. all of the secondaries with diodes are outputs. so on T731 only pins 5,6,7 are inputs, this is your primary side. on T721 pins 7,5 are your input, pins 2,3 are feedback to the switcher chip, all others are secondaries (outputs). you need the cpu to tell the power supply to start up. without that nothing's going to happen.
Thanks unclejed for sticking with me on this, I know it's not easy! (for me anyway, it isn't)
When you say the cpu needs to startup the switchers, do you mean that the relay Ry721 is tripped & PS then flows through main switcher T701 which produces VDD which then feeds T731?
In the first post I made on this I explain the details of what I did but just to clarify, I effectively bypassed the relay by feeding +20V to LB731 while leaving the rest of the circuit plugged in for the standby circuit. This worked (and sounded great) but after about 10-15mins the main switching IC701 begins to make clicking noises at which point I trn off.
Any ideas what's causing this or how to stop it?
PS. I think the circuit to the right of the main switcher T701 has some AC current going through it?
When you say the cpu needs to startup the switchers, do you mean that the relay Ry721 is tripped & PS then flows through main switcher T701 which produces VDD which then feeds T731?
In the first post I made on this I explain the details of what I did but just to clarify, I effectively bypassed the relay by feeding +20V to LB731 while leaving the rest of the circuit plugged in for the standby circuit. This worked (and sounded great) but after about 10-15mins the main switching IC701 begins to make clicking noises at which point I trn off.
Any ideas what's causing this or how to stop it?
PS. I think the circuit to the right of the main switcher T701 has some AC current going through it?
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