I am about to build a F6 and am trying to understand how a dual mono setup would work.
Is the above correct (standard on left, dual mono on right)?
- Should I be using 2 x 200VA transformers instead of 2 x 400VA transformers? Or is this a cost concern? I already have 2 x 400VA transformers on hand.
- I was not planning on using inrush current provision, besides the CL60 thermistors, should I be using the Soft Start Board since I am doubling the inrush current? I could also implement 2 separate power switches for the L and R channels to offset the surges which would be a simple solution?
- Any other comments/suggestions before I proceed with the build?
Is the above correct (standard on left, dual mono on right)?
- Should I be using 2 x 200VA transformers instead of 2 x 400VA transformers? Or is this a cost concern? I already have 2 x 400VA transformers on hand.
- I was not planning on using inrush current provision, besides the CL60 thermistors, should I be using the Soft Start Board since I am doubling the inrush current? I could also implement 2 separate power switches for the L and R channels to offset the surges which would be a simple solution?
- Any other comments/suggestions before I proceed with the build?
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left standard , right dual mono
250VA would be minimum for Donut /channel , in my book
400VA/channel even better ; name of the game is brute force approach , if possible
use one CL60 per xformer and any other type of sort start is ....... waste of time
250VA would be minimum for Donut /channel , in my book
400VA/channel even better ; name of the game is brute force approach , if possible
use one CL60 per xformer and any other type of sort start is ....... waste of time
mhm, is it right that i need TWO boards of the diy audio universal PSU´s for dual mono? I first thought I just do the cabeling a different way, but as far is see.... I end up with two PSU boards.
if anybody has experience with the boards..?
thanks
stefan
if anybody has experience with the boards..?
thanks
stefan
If you are doing dual mono in the one chassis, you have to take care with the input to avoid earth loops.
From memory you only connect one rca ground wire to the amplifier (not both), but I'm sure Zen Mod has other clever ways.
I just like dual mono in separate chassis (my brain does less work) or do the powerysupply like Nelson's F6 with single transformer where each channel has it's own independent pair of output caps (very clever way he did it) coming off the PSU. The way he did it, gets you very close to full dual mono.
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dual mono in one case - each (channel's) audio (central point) GND is having own CL connected to chassis
inputs fully isolated from chassis and that's it
inputs fully isolated from chassis and that's it
thank you ZM and AE,
i guess i can go to each single channel, signal board or PSU with the RCA ground. left to left channel and right to right.
In my current (quite crappy) F5 building I have two torroids and one PSU board with a shared Starground and it works really good without hum...
I just wantet to upgrade with the two universal PSUs this winter because of old Elkos and little hot Diodes in the old one.
again, thanks for sharing
st.
what is a "CL connection" (yes no shame, immediate question 🙂 )
and if its single parts (cap, coil?) how to do the dimensioning? I didn´t do it in my current.
thanks,
st.
and if its single parts (cap, coil?) how to do the dimensioning? I didn´t do it in my current.
thanks,
st.
Independent CL60.
Go back and look at firstwatt psu circuits. It will become clear.
It never really occured to me what is happening till Zen Mod explained his way then the light turned on.
Go back and look at firstwatt psu circuits. It will become clear.
It never really occured to me what is happening till Zen Mod explained his way then the light turned on.
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I am always follow advice of Ben Duncan, a British audio expert : One piece of audio equipment ,power amp, should have enclosure tied to mains earth tab and then audio ground directly connected to case near to that point. All other eq. should have audio grounds isolated by resistors , diode bridges or thermistors. It was a long time ago, and honestly I forgot his arguments and explanations but I think it was something about reducing influence of transformer leakage inductance. All in all, less sensitive point in the system (power amp or headphone amp) should have direct connection between mains earth and signal ground.
In this way, my audio system, even with phono preamp, is hum and buzz free.
In this way, my audio system, even with phono preamp, is hum and buzz free.
I built my Aleph J with dual power supplies. You can see the stacked transformers and separate PSU boards, each one with its own CL60 dropped directly to the chassis, following the link below:
http://www.diyaudio.com/forums/pass-labs/224881-aleph-j-universal-mounting-spec-13.html#post3481260
http://www.diyaudio.com/forums/pass-labs/224881-aleph-j-universal-mounting-spec-13.html#post3481260
I thought NP said that for dual paralleled 120V primaries (like in the USA), to use a CL60
in series with each primary winding, which are then in parallel.
Rayma,
You are talking about different things. The NTC thermistor in series with the transformer's primary limits the inrush current at power up. The NTC thermistor used between the PSU ground and chassis ground adds a little resistance which should reduce the occurrence of ground loops. At the same time, in case of component failure, that thermistor still provides a safe connection to ground.
You are talking about different things. The NTC thermistor in series with the transformer's primary limits the inrush current at power up. The NTC thermistor used between the PSU ground and chassis ground adds a little resistance which should reduce the occurrence of ground loops. At the same time, in case of component failure, that thermistor still provides a safe connection to ground.
Did I get it right? Green are GND lines. Dual CL60's on each transformer since I am using single 230V primaries?
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