Getting ready to do wopl 400 build
- Thread starter roccus
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chassis wiring
Tomorrow I am going to run the wires from the transformer and fuse holders they have all be chopped short and be good to put all new anyway.. I have been reading around a bit on this and if I have this right you guys run all power wires AC and DC along the bottom so the only wires along the top end up being the wires to the speaker terminal right?? But.. what about the 2 wires to the light board, bottom also?
Tomorrow I am going to run the wires from the transformer and fuse holders they have all be chopped short and be good to put all new anyway.. I have been reading around a bit on this and if I have this right you guys run all power wires AC and DC along the bottom so the only wires along the top end up being the wires to the speaker terminal right?? But.. what about the 2 wires to the light board, bottom also?
Chassis wired
Have to get a new power cord the original was worn to bare wire in a spot from rubbing against the corner of the transformer I will run the cord lead under the caps along the bottom and up to the thermal switch... should I put the common to the fuse or the switch or does it make any difference?
Have to get a new power cord the original was worn to bare wire in a spot from rubbing against the corner of the transformer I will run the cord lead under the caps along the bottom and up to the thermal switch... should I put the common to the fuse or the switch or does it make any difference?
If you're using a three prong power cable do not connect the earth ground wire - leave it floating. The consensus is this may cause a ground loop and the result of that the ground loop could cause hum. I've collected a few of Joe's and Lee's posts and I've included them for reference - see below:
NEITHER side of the AC line should EVER be considered groundand should ALWAYS be isolated from chassis (it is a violation of just aboutevery safety agency to do otherwise). The 3 prong IEC C13 type connectorprovides for the 2 isolated AC inputs plus a 3rd safety (non-isolated) ground.The safety ground purpose is to tie the chassis to the ground stake in yourhouse which usually is driven into the earth near your circuit breaker box. Inthe event that the insulation of one of the isolated AC inputs breaks down andshorts to the chassis, it provides a path for the resulting current to thisearth ground which in turn pops your circuit breaker and preserves humansafety. Without the safety ground, this AC isolation breakdown would end up energizingthe chassis and presenting a human shock hazard.
With that said, using the third wire safety ground to tie tothe chassis in your Phase Linear is asking for ground loop problems whichusually always shows up as hum. This is because the DC ground in the PhaseLinear is also tied directly to the chassis. To be successful in adding the IECsafety ground attachment to your Phase Linear chassis, you will have to isolatethe amp DC ground from the chassis at the multiple tie points that are in theoriginal design (I think there are 2 of them, the middle leg of the two small 3terminal barrier strips on the amp back wall). Since I have never tried this, Ido not know what "other" noise problems will result from isolatingthe Phase Linear chassis from DC ground and I would have to resort to the"your mileage may vary" phrase.
I don't know if this is helpful at all or not.
More from Joe (Gepetto);
All Phase Linear boards that I have run across have 2different grounds entering the board near the bottom. Phase did not use adifferent ground symbol on their schematics which makes it confusing. There isa signal ground and a chassis ground. The signal ground is GENERALLY a blackwire that originates from the ground connecting the 2 RCA input jacks, thisalso connects to the chassis near the RCA jacks. In the PL400 this ground isGENERALLY delivered to the preamp board using twisted pair wiring. In thePL700B it is GENERALLY via shielded coax cable. All the sensitive low levelanalog signal grounds on the board are connected to this ground node. Theseground nodes are kept separate on the board one for the right and one for theleft channel. The signal ground comes in via pin 2 on the bottom edge of eachchannel at the bottom of the PCB. Connections to this ground are: R3, C6, Q3-Cfor each channel.
The other ground is chassis ground and GENERALLY isconnected to the PCB via a white wire that originates at the same chassisconnection near the RCA jack connection. On Phase Linear boards both channelsare connected to this same ground wire, the traces are combined into one forthis ground type. The power bypass caps C3 on each channel of the PCB areconnected to this ground as well as C10 on each channel as well as the cathodeof D11 and anode of D12 (these are the diode clamps used in the output currentlimit protection circuitry). There is a resistive connection between signalground and chassis ground on the PCB. The left channel uses a 56 ohm resistorto connect these 2 grounds and the right channel uses a 2.7 ohm resistor. Idon't know why they are of a different value but they consistently are thesevalues. The speaker returns GENERALLY go directly from the binding postnegative back to the POWER ground node that is the copper bus bar between the 2large bulk caps mounted on the transformer. There is GENERALLY a connectionfrom this copper bus bar to the chassis ground via a small 3 lug terminal stripmounted to the aluminum chassis.
Phase Linear really does not have a true single point groundin any configurations I have seen. The aluminum chassis serves as this single point ground.
Hope this helps out rather than confuse. Ask any questionsthat you have. Thx.
More;
You will note on the White Oak board that the signal ground(pin 2) is paired with the signal input from the RCA jack (pin 1) andphysically away from the other signals and connections. This separation is onpurpose to keep the lowest signal levels on the board isolated from the largersignal areas. You will also notice that the input signal from pin 1 is a clean,straight run up to the top of the board with an adjacent signal ground run. Allto keep the signal to noise ratio as good as possible.<o
></o>
More on the board grounding from Gepetto;
Without confusing this any further Lee, I'll mention thatthe White Oak board has the option to totally separate both Chassis (CH_GND)and Signal (GND) grounds on the PCB. The signal grounds coming in on pin 2L andpin 2R are ALWAYS totally separate. The Chassis grounds are joined by the 24AWBbus wire jumper that you installed on the back of the board between pad 5L1 and5R1.
This was to allow flexibility to change the ground schemeused in the Phase Linear if desired. This option does not exist on the PhaseLinear boards. I suspect that there is a better ground and power distributionscheme that can be configured within the Phase chassis and one day when I havesome spare time, I intend to prove that The +75/100V rails and -75/100V railsare also totally independent on the White Oak board for this same reason. Theseare also conjoined by the other 2 bus wire jumpers (11L1 and 11R1 and 12L1 and12L2).
NEITHER side of the AC line should EVER be considered groundand should ALWAYS be isolated from chassis (it is a violation of just aboutevery safety agency to do otherwise). The 3 prong IEC C13 type connectorprovides for the 2 isolated AC inputs plus a 3rd safety (non-isolated) ground.The safety ground purpose is to tie the chassis to the ground stake in yourhouse which usually is driven into the earth near your circuit breaker box. Inthe event that the insulation of one of the isolated AC inputs breaks down andshorts to the chassis, it provides a path for the resulting current to thisearth ground which in turn pops your circuit breaker and preserves humansafety. Without the safety ground, this AC isolation breakdown would end up energizingthe chassis and presenting a human shock hazard.
With that said, using the third wire safety ground to tie tothe chassis in your Phase Linear is asking for ground loop problems whichusually always shows up as hum. This is because the DC ground in the PhaseLinear is also tied directly to the chassis. To be successful in adding the IECsafety ground attachment to your Phase Linear chassis, you will have to isolatethe amp DC ground from the chassis at the multiple tie points that are in theoriginal design (I think there are 2 of them, the middle leg of the two small 3terminal barrier strips on the amp back wall). Since I have never tried this, Ido not know what "other" noise problems will result from isolatingthe Phase Linear chassis from DC ground and I would have to resort to the"your mileage may vary" phrase.
I don't know if this is helpful at all or not.
More from Joe (Gepetto);
All Phase Linear boards that I have run across have 2different grounds entering the board near the bottom. Phase did not use adifferent ground symbol on their schematics which makes it confusing. There isa signal ground and a chassis ground. The signal ground is GENERALLY a blackwire that originates from the ground connecting the 2 RCA input jacks, thisalso connects to the chassis near the RCA jacks. In the PL400 this ground isGENERALLY delivered to the preamp board using twisted pair wiring. In thePL700B it is GENERALLY via shielded coax cable. All the sensitive low levelanalog signal grounds on the board are connected to this ground node. Theseground nodes are kept separate on the board one for the right and one for theleft channel. The signal ground comes in via pin 2 on the bottom edge of eachchannel at the bottom of the PCB. Connections to this ground are: R3, C6, Q3-Cfor each channel.
The other ground is chassis ground and GENERALLY isconnected to the PCB via a white wire that originates at the same chassisconnection near the RCA jack connection. On Phase Linear boards both channelsare connected to this same ground wire, the traces are combined into one forthis ground type. The power bypass caps C3 on each channel of the PCB areconnected to this ground as well as C10 on each channel as well as the cathodeof D11 and anode of D12 (these are the diode clamps used in the output currentlimit protection circuitry). There is a resistive connection between signalground and chassis ground on the PCB. The left channel uses a 56 ohm resistorto connect these 2 grounds and the right channel uses a 2.7 ohm resistor. Idon't know why they are of a different value but they consistently are thesevalues. The speaker returns GENERALLY go directly from the binding postnegative back to the POWER ground node that is the copper bus bar between the 2large bulk caps mounted on the transformer. There is GENERALLY a connectionfrom this copper bus bar to the chassis ground via a small 3 lug terminal stripmounted to the aluminum chassis.
Phase Linear really does not have a true single point groundin any configurations I have seen. The aluminum chassis serves as this single point ground.
Hope this helps out rather than confuse. Ask any questionsthat you have. Thx.
More;
You will note on the White Oak board that the signal ground(pin 2) is paired with the signal input from the RCA jack (pin 1) andphysically away from the other signals and connections. This separation is onpurpose to keep the lowest signal levels on the board isolated from the largersignal areas. You will also notice that the input signal from pin 1 is a clean,straight run up to the top of the board with an adjacent signal ground run. Allto keep the signal to noise ratio as good as possible.<o
></o>More on the board grounding from Gepetto;
Without confusing this any further Lee, I'll mention thatthe White Oak board has the option to totally separate both Chassis (CH_GND)and Signal (GND) grounds on the PCB. The signal grounds coming in on pin 2L andpin 2R are ALWAYS totally separate. The Chassis grounds are joined by the 24AWBbus wire jumper that you installed on the back of the board between pad 5L1 and5R1.
This was to allow flexibility to change the ground schemeused in the Phase Linear if desired. This option does not exist on the PhaseLinear boards. I suspect that there is a better ground and power distributionscheme that can be configured within the Phase chassis and one day when I havesome spare time, I intend to prove that The +75/100V rails and -75/100V railsare also totally independent on the White Oak board for this same reason. Theseare also conjoined by the other 2 bus wire jumpers (11L1 and 11R1 and 12L1 and12L2).
Last edited:
If you're using a three prong power cable do not connect the earth ground wire - leave it floating. The consensus is this may cause a ground loop and the result of that the ground loop could cause hum. I've collected a few of Joe's and Lee's posts and I've included them for reference - see below:
NEITHER side of the AC line should EVER be considered groundand should ALWAYS be isolated from chassis (it is a violation of just aboutevery safety agency to do otherwise). The 3 prong IEC C13 type connectorprovides for the 2 isolated AC inputs plus a 3rd safety (non-isolated) ground.The safety ground purpose is to tie the chassis to the ground stake in yourhouse which usually is driven into the earth near your circuit breaker box. Inthe event that the insulation of one of the isolated AC inputs breaks down andshorts to the chassis, it provides a path for the resulting current to thisearth ground which in turn pops your circuit breaker and preserves humansafety. Without the safety ground, this AC isolation breakdown would end up energizingthe chassis and presenting a human shock hazard.
With that said, using the third wire safety ground to tie tothe chassis in your Phase Linear is asking for ground loop problems whichusually always shows up as hum. This is because the DC ground in the PhaseLinear is also tied directly to the chassis. To be successful in adding the IECsafety ground attachment to your Phase Linear chassis, you will have to isolatethe amp DC ground from the chassis at the multiple tie points that are in theoriginal design (I think there are 2 of them, the middle leg of the two small 3terminal barrier strips on the amp back wall). Since I have never tried this, Ido not know what "other" noise problems will result from isolatingthe Phase Linear chassis from DC ground and I would have to resort to the"your mileage may vary" phrase.
I don't know if this is helpful at all or not.
More from Joe (Gepetto);
All Phase Linear boards that I have run across have 2different grounds entering the board near the bottom. Phase did not use adifferent ground symbol on their schematics which makes it confusing. There isa signal ground and a chassis ground. The signal ground is GENERALLY a blackwire that originates from the ground connecting the 2 RCA input jacks, thisalso connects to the chassis near the RCA jacks. In the PL400 this ground isGENERALLY delivered to the preamp board using twisted pair wiring. In thePL700B it is GENERALLY via shielded coax cable. All the sensitive low levelanalog signal grounds on the board are connected to this ground node. Theseground nodes are kept separate on the board one for the right and one for theleft channel. The signal ground comes in via pin 2 on the bottom edge of eachchannel at the bottom of the PCB. Connections to this ground are: R3, C6, Q3-Cfor each channel.
The other ground is chassis ground and GENERALLY isconnected to the PCB via a white wire that originates at the same chassisconnection near the RCA jack connection. On Phase Linear boards both channelsare connected to this same ground wire, the traces are combined into one forthis ground type. The power bypass caps C3 on each channel of the PCB areconnected to this ground as well as C10 on each channel as well as the cathodeof D11 and anode of D12 (these are the diode clamps used in the output currentlimit protection circuitry). There is a resistive connection between signalground and chassis ground on the PCB. The left channel uses a 56 ohm resistorto connect these 2 grounds and the right channel uses a 2.7 ohm resistor. Idon't know why they are of a different value but they consistently are thesevalues. The speaker returns GENERALLY go directly from the binding postnegative back to the POWER ground node that is the copper bus bar between the 2large bulk caps mounted on the transformer. There is GENERALLY a connectionfrom this copper bus bar to the chassis ground via a small 3 lug terminal stripmounted to the aluminum chassis.
Phase Linear really does not have a true single point groundin any configurations I have seen. The aluminum chassis serves as this single point ground.
Hope this helps out rather than confuse. Ask any questionsthat you have. Thx.
More;
You will note on the White Oak board that the signal ground(pin 2) is paired with the signal input from the RCA jack (pin 1) andphysically away from the other signals and connections. This separation is onpurpose to keep the lowest signal levels on the board isolated from the largersignal areas. You will also notice that the input signal from pin 1 is a clean,straight run up to the top of the board with an adjacent signal ground run. Allto keep the signal to noise ratio as good as possible.<o></o
More on the board grounding from Gepetto;
Without confusing this any further Lee, I'll mention thatthe White Oak board has the option to totally separate both Chassis (CH_GND)and Signal (GND) grounds on the PCB. The signal grounds coming in on pin 2L andpin 2R are ALWAYS totally separate. The Chassis grounds are joined by the 24AWBbus wire jumper that you installed on the back of the board between pad 5L1 and5R1.
This was to allow flexibility to change the ground schemeused in the Phase Linear if desired. This option does not exist on the PhaseLinear boards. I suspect that there is a better ground and power distributionscheme that can be configured within the Phase chassis and one day when I havesome spare time, I intend to prove that The +75/100V rails and -75/100V railsare also totally independent on the White Oak board for this same reason. Theseare also conjoined by the other 2 bus wire jumpers (11L1 and 11R1 and 12L1 and12L2).
NEITHER side of the AC line should EVER be considered groundand should ALWAYS be isolated from chassis (it is a violation of just aboutevery safety agency to do otherwise). The 3 prong IEC C13 type connectorprovides for the 2 isolated AC inputs plus a 3rd safety (non-isolated) ground.The safety ground purpose is to tie the chassis to the ground stake in yourhouse which usually is driven into the earth near your circuit breaker box. Inthe event that the insulation of one of the isolated AC inputs breaks down andshorts to the chassis, it provides a path for the resulting current to thisearth ground which in turn pops your circuit breaker and preserves humansafety. Without the safety ground, this AC isolation breakdown would end up energizingthe chassis and presenting a human shock hazard.
With that said, using the third wire safety ground to tie tothe chassis in your Phase Linear is asking for ground loop problems whichusually always shows up as hum. This is because the DC ground in the PhaseLinear is also tied directly to the chassis. To be successful in adding the IECsafety ground attachment to your Phase Linear chassis, you will have to isolatethe amp DC ground from the chassis at the multiple tie points that are in theoriginal design (I think there are 2 of them, the middle leg of the two small 3terminal barrier strips on the amp back wall). Since I have never tried this, Ido not know what "other" noise problems will result from isolatingthe Phase Linear chassis from DC ground and I would have to resort to the"your mileage may vary" phrase.
I don't know if this is helpful at all or not.
More from Joe (Gepetto);
All Phase Linear boards that I have run across have 2different grounds entering the board near the bottom. Phase did not use adifferent ground symbol on their schematics which makes it confusing. There isa signal ground and a chassis ground. The signal ground is GENERALLY a blackwire that originates from the ground connecting the 2 RCA input jacks, thisalso connects to the chassis near the RCA jacks. In the PL400 this ground isGENERALLY delivered to the preamp board using twisted pair wiring. In thePL700B it is GENERALLY via shielded coax cable. All the sensitive low levelanalog signal grounds on the board are connected to this ground node. Theseground nodes are kept separate on the board one for the right and one for theleft channel. The signal ground comes in via pin 2 on the bottom edge of eachchannel at the bottom of the PCB. Connections to this ground are: R3, C6, Q3-Cfor each channel.
The other ground is chassis ground and GENERALLY isconnected to the PCB via a white wire that originates at the same chassisconnection near the RCA jack connection. On Phase Linear boards both channelsare connected to this same ground wire, the traces are combined into one forthis ground type. The power bypass caps C3 on each channel of the PCB areconnected to this ground as well as C10 on each channel as well as the cathodeof D11 and anode of D12 (these are the diode clamps used in the output currentlimit protection circuitry). There is a resistive connection between signalground and chassis ground on the PCB. The left channel uses a 56 ohm resistorto connect these 2 grounds and the right channel uses a 2.7 ohm resistor. Idon't know why they are of a different value but they consistently are thesevalues. The speaker returns GENERALLY go directly from the binding postnegative back to the POWER ground node that is the copper bus bar between the 2large bulk caps mounted on the transformer. There is GENERALLY a connectionfrom this copper bus bar to the chassis ground via a small 3 lug terminal stripmounted to the aluminum chassis.
Phase Linear really does not have a true single point groundin any configurations I have seen. The aluminum chassis serves as this single point ground.
Hope this helps out rather than confuse. Ask any questionsthat you have. Thx.
More;
You will note on the White Oak board that the signal ground(pin 2) is paired with the signal input from the RCA jack (pin 1) andphysically away from the other signals and connections. This separation is onpurpose to keep the lowest signal levels on the board isolated from the largersignal areas. You will also notice that the input signal from pin 1 is a clean,straight run up to the top of the board with an adjacent signal ground run. Allto keep the signal to noise ratio as good as possible.<o
></oMore on the board grounding from Gepetto;
Without confusing this any further Lee, I'll mention thatthe White Oak board has the option to totally separate both Chassis (CH_GND)and Signal (GND) grounds on the PCB. The signal grounds coming in on pin 2L andpin 2R are ALWAYS totally separate. The Chassis grounds are joined by the 24AWBbus wire jumper that you installed on the back of the board between pad 5L1 and5R1.
This was to allow flexibility to change the ground schemeused in the Phase Linear if desired. This option does not exist on the PhaseLinear boards. I suspect that there is a better ground and power distributionscheme that can be configured within the Phase chassis and one day when I havesome spare time, I intend to prove that The +75/100V rails and -75/100V railsare also totally independent on the White Oak board for this same reason. Theseare also conjoined by the other 2 bus wire jumpers (11L1 and 11R1 and 12L1 and12L2).
Have to get a new power cord the original was worn to bare wire in a spot from rubbing against the corner of the transformer I will run the cord lead under the caps along the bottom and up to the thermal switch... should I put the common to the fuse or the switch or does it make any difference?
ONLY AC on top.
ALL DC on bottom
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The 2 red wires you see going across the top come out of the left side of the transformer I believe they will go to the light board so across the top and down is correct right? Then the black and red wire you see along the bottom then go up the center come off the power cap lugs so they should be across the top? I think those will power the control board. All the wires that came out of the left side of the transformer were cut real short that is the way I got it so I pulled the transformer off and did all splices behind the transformer mount plate so they can't be seen. I did not like the way the 2 yellow wires were ran from factory across boards so I just twisted the 2 together with the splice under the lower cap so it is not easily seen then ran the wire along the bottom up to the switch. Not having the boards here I am not sure where all the wires will end up so I went long with them will cut them and tweak all wires to look nice once I see where everything goes.