Re: A possible best of both worlds?
Well, you can always compare it to a setup without isolation transformer. While isolation TX, especially when wired for balanced power, seem to improve certain aspects, they also influence other things and not neccessary for better, so for me their use is always questionable. Of course, the actual gains will depend on local mains condition.
PS: I just noticed those are 240V Plitrons, so indeed you have no choice but to be happy 😉
rickmcinnis said:
Well, you can always compare it to a setup without isolation transformer. While isolation TX, especially when wired for balanced power, seem to improve certain aspects, they also influence other things and not neccessary for better, so for me their use is always questionable. Of course, the actual gains will depend on local mains condition.
PS: I just noticed those are 240V Plitrons, so indeed you have no choice but to be happy 😉
HI
if I remember well , piltron test for 60hz , in EE with 50hz can buzz....!! ??
PS Ayre use EI...
if I remember well , piltron test for 60hz , in EE with 50hz can buzz....!! ??
PS Ayre use EI...
I too have a Plitron, Anvel, and Sumr transformer I will be comparing. Since they all vary in size and voltage and lacking proper test equipment performance can only be subjective. However noise fit and finish can be evaluated. I also rescued a computer isolation transformer I was going to play around with. My ceiling fans and fridge seem to make my transformers buzz so I will use that as a basis of judgment.
Bill
Bill
Hey what about using the Hammond 182G18
2 X 18volts @6.25 A . I have about 20 of them kicking around.
I could use 2 per channel giving 2 x 18volts @12.5 A that would use up lots of real estate but spread out the heat somewhat.
2 X 18volts @6.25 A . I have about 20 of them kicking around.
I could use 2 per channel giving 2 x 18volts @12.5 A that would use up lots of real estate but spread out the heat somewhat.
ichiban said:
Progress is slow for me, but still commited to the shootout.
I've had the 'default' F5 running for awhile now - with a Plitron.
The Plitron has a little mechanical hum in this configuration (cant hear it away from amp). The sounds of the amp keeps on opening up, so something must be breaking in.
The second chassis is now a box, just needs input and outputs drilled in, and wiring up the R-Core based Power Supply. The electronics have been tested, so hope all goes well there. The Power section is all hooked up with Euroblocks, so it wont take long at all to swap stuff around.
Once the second amp is done, I can harvest the Antek out of my F2 to try that out.
Update
I have currently tested the R-Core and Plitron for the Bass setup.
Here is the current deal. The 13.5 Heatinks and the sideways setup of the R-Core (so it will fit) produces a minor amount of hum. (Like a triode amp). It's actually acceptable for the bass, but not the mid-highs. So my second amp I am going to extend the R-Core out with some Euro-blocks this weekend.
THat said, listening to the Bass on the R-Core compared to the Plitron, there appears to be a little more weight to it. It appears minor, and I want to test this again.
This does not bode well for an R-Core in my current setup, unless a mod the chassis so the tranny mounts vertically to the chassis.
Not as easy as I want it to be.
I have currently tested the R-Core and Plitron for the Bass setup.
Here is the current deal. The 13.5 Heatinks and the sideways setup of the R-Core (so it will fit) produces a minor amount of hum. (Like a triode amp). It's actually acceptable for the bass, but not the mid-highs. So my second amp I am going to extend the R-Core out with some Euro-blocks this weekend.
THat said, listening to the Bass on the R-Core compared to the Plitron, there appears to be a little more weight to it. It appears minor, and I want to test this again.
This does not bode well for an R-Core in my current setup, unless a mod the chassis so the tranny mounts vertically to the chassis.
Not as easy as I want it to be.
Interesting thread. Will read slowly tomorrow.
My Plitron doesnt buzz at all. Everything in my amp is dead quiet.
nicoch46 said:
My Plitron doesnt buzz at all. Everything in my amp is dead quiet.
labjr said:
both amps with either transformer has a small mechanical buzz.
Might be the power supply or F5 Curcuit. LabJr has heard it.
The larger R-Core in my small chassis can produce a little hum in the speakers if you listen closely. It's enough to annoy me. I hope to get some listening on both trannies soon. Been busy with spring duties.
If anyone's has some recommendations on recordings to test with I am all ears
Actually, I might have it if it's a fairly common recording.Hi Tea Bag,
if you can hear differences in the hum volume you can certainly measure them.
Connect a DMM with 200.0mVac full scale to the speaker terminals.
And watch how the readings change as you rotate or move the transformer around. Take care to ensure you cannot touch the mains terminals.
Temporary long flexible leads (300mm?) to the transformers will help tremendously during this experiment.
if you can hear differences in the hum volume you can certainly measure them.
Connect a DMM with 200.0mVac full scale to the speaker terminals.
And watch how the readings change as you rotate or move the transformer around. Take care to ensure you cannot touch the mains terminals.
Temporary long flexible leads (300mm?) to the transformers will help tremendously during this experiment.
AndrewT said:
Andrew, I configured a longer pigtail for the R-Core. That will allow me to run it out of chassis.
I didn't think of measureing it, I was just moving it around in the small jail cell.
My only problem is if I get stuck on using the R-Core, I got to use a new chassis...
Certainly had the Main's AC to close to the left channel once - trying to get this figured out, and that was even worse, but the same effect. FYI.
R-Core vs Plitron
Okay,
A few things,
I have two of the R-Cores. They both produce a little hum, in either amplifier, long pigtail or not. I am not sure of the potential reasoning for this. It does not appear to be a problem of getting AC too near the output boards. So I am not sure if it's a quality issue with the R-Cores.
The Plitrons dont have any noise from them, other than some mechanical hum. The R-Core has this as well. I am not sure if this translates into some hum induced into the R-Core only. Suggestions welcome.
I spent the day listening to:
Mindy Smith - Come to Jesus (no I am not a Bible thumper!) Bass, voice
Madonna - Frozen (wide soundstage)
Willie Nelson - American Tune, other tunes from Teatro. Good drums.
Belinda Carlise - Terpentine, vocals.
Yes they do sound different, but I could not tell you which is better or worse, or if there are other factors in play.
I would say if I had to, I think the Plitron is a bit more musical, vocals minorly less distinct. The R-Core seems to have an distinction in the vocals, I am not sure that it is for the good, or distortion, or what.
The music ensembles on the R-Cores seem less distinct.
If am monitoring the bias and offset of these units, and the transformers don't change things around much here, if anything.
What I can tell, as I may have said before, is that warm up time is important for anything to sounds quite good here. I would say in my system 1 1/2 hours is about good.
The Antek toroid is next.
I think the R-Core is out of contention, unless the noise issue can be gotten rid of.🙁
Oh, well they may operate fine in another circuit. They may just be too noisy for audio. I will let the engineering minds discuss this if they have some troubleshooting suggestions.
Okay,
A few things,
I have two of the R-Cores. They both produce a little hum, in either amplifier, long pigtail or not. I am not sure of the potential reasoning for this. It does not appear to be a problem of getting AC too near the output boards. So I am not sure if it's a quality issue with the R-Cores.
The Plitrons dont have any noise from them, other than some mechanical hum. The R-Core has this as well. I am not sure if this translates into some hum induced into the R-Core only. Suggestions welcome.
I spent the day listening to:
Mindy Smith - Come to Jesus (no I am not a Bible thumper!) Bass, voice
Madonna - Frozen (wide soundstage)
Willie Nelson - American Tune, other tunes from Teatro. Good drums.
Belinda Carlise - Terpentine, vocals.
Yes they do sound different, but I could not tell you which is better or worse, or if there are other factors in play.
I would say if I had to, I think the Plitron is a bit more musical, vocals minorly less distinct. The R-Core seems to have an distinction in the vocals, I am not sure that it is for the good, or distortion, or what.
The music ensembles on the R-Cores seem less distinct.If am monitoring the bias and offset of these units, and the transformers don't change things around much here, if anything.
What I can tell, as I may have said before, is that warm up time is important for anything to sounds quite good here. I would say in my system 1 1/2 hours is about good.
The Antek toroid is next.
I think the R-Core is out of contention, unless the noise issue can be gotten rid of.🙁
Oh, well they may operate fine in another circuit. They may just be too noisy for audio. I will let the engineering minds discuss this if they have some troubleshooting suggestions.
Re: R-Core vs Plitron
Hi,
When I first connected my F5 to speakers there was a lot of noise/hum. At first I thought it was a grounding problem, but messing with the signal ground point (to amp board, to ground star, etc) did not make much impact. It wasn't a typical low 60hz hum, but rather a higher pitched crackly/staticky hum, so I wrapped some magnet shield from lessemf.com ($4.50 for a 4"x12" strip) around the toroid and it reduced noise by half. Re-reading Nelson Pass's comments on noise in the 6moons article I shielded my inputs (drain connected to input rca seemed marginally better than at amp board) and used a braid shielded interconnect to get the noise to almost zero. I will probably have to move my input to the opposit side of the amp (from the speaker and power) to reduce it any further. For reference, I have a 300va antek which starts to have some mechanical hum past 120v.
Tea-Bag said:Okay,
A few things,
I have two of the R-Cores. They both produce a little hum, in either amplifier, long pigtail or not. I am not sure of the potential reasoning for this. It does not appear to be a problem of getting AC too near the output boards. So I am not sure if it's a quality issue with the R-Cores.
The Plitrons dont have any noise from them, other than some mechanical hum. The R-Core has this as well. I am not sure if this translates into some hum induced into the R-Core only. Suggestions welcome.
I spent the day listening to:
Mindy Smith - Come to Jesus (no I am not a Bible thumper!) Bass, voice
Madonna - Frozen (wide soundstage)
Willie Nelson - American Tune, other tunes from Teatro. Good drums.
Belinda Carlise - Terpentine, vocals.
Yes they do sound different, but I could not tell you which is better or worse, or if there are other factors in play.
I would say if I had to, I think the Plitron is a bit more musical, vocals minorly less distinct. The R-Core seems to have an distinction in the vocals, I am not sure that it is for the good, or distortion, or what.
If am monitoring the bias and offset of these units, and the transformers don't change things around much here, if anything.
What I can tell, as I may have said before, is that warm up time is important for anything to sounds quite good here. I would say in my system 1 1/2 hours is about good.
The Antek toroid is next.
I think the R-Core is out of contention, unless the noise issue can be gotten rid of.🙁
Oh, well they may operate fine in another circuit. They may just be too noisy for audio. I will let the engineering minds discuss this if they have some troubleshooting suggestions.
Hi,
When I first connected my F5 to speakers there was a lot of noise/hum. At first I thought it was a grounding problem, but messing with the signal ground point (to amp board, to ground star, etc) did not make much impact. It wasn't a typical low 60hz hum, but rather a higher pitched crackly/staticky hum, so I wrapped some magnet shield from lessemf.com ($4.50 for a 4"x12" strip) around the toroid and it reduced noise by half. Re-reading Nelson Pass's comments on noise in the 6moons article I shielded my inputs (drain connected to input rca seemed marginally better than at amp board) and used a braid shielded interconnect to get the noise to almost zero. I will probably have to move my input to the opposit side of the amp (from the speaker and power) to reduce it any further. For reference, I have a 300va antek which starts to have some mechanical hum past 120v.
Re: Re: R-Core vs Plitron
Alazira,
Thanks for the advice.
I am not sure the shielding would be needed, at least from the transformer itself, since I ran a pig tail having the transformer a foot or more away with little audible difference. The hum I get out the speakers seems to be 60hz. It's interesting the Plitrons don't do it. I think something else is in play, but I may swap with shielded inputs on one of the amps to make sure. I am running Kimber TCSS, the twisted stuff.
My AC is right at 120v, not 115.
alazira said:
Alazira,
Thanks for the advice.
I am not sure the shielding would be needed, at least from the transformer itself, since I ran a pig tail having the transformer a foot or more away with little audible difference. The hum I get out the speakers seems to be 60hz. It's interesting the Plitrons don't do it. I think something else is in play, but I may swap with shielded inputs on one of the amps to make sure. I am running Kimber TCSS, the twisted stuff.
My AC is right at 120v, not 115.
Tea-Bag said:
If anyone's has some recommendations on recordings to test with I am all ears
To test bass, my favorite track is "martika's kitchen" by Crooked Still from their album "shaken by a low sound."
alazira said:
Crooked Still looks like an excellent new group to try, however I did not see this track on the album list on amazonian.
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