Hi Lucpes and Ray: 🙂
My pre is transformer based: it had 0 VDC the last time I checked.
Signal level is OK.
My 400ST has OPA 2134. I see coupling caps (elco) before opamp (and SMD input section).
I will check it again. Perhaps I missed something.
Thanks a lot 🙂
M
My pre is transformer based: it had 0 VDC the last time I checked.
Signal level is OK.
My 400ST has OPA 2134. I see coupling caps (elco) before opamp (and SMD input section).
I will check it again. Perhaps I missed something.
Thanks a lot 🙂
M
Hi,
Guys it's discussed in this very thread. The coupling caps were shifted around on the 400's, from before, and back to after the op amp. It's not unreasonable to think maxlorenze simply has an oddball.
Henrik Juhl, Hi.
I'm sorry to have to say, no.
Due to constant revisions and improvements, there's no set cookbook to hot rod them, additionally it's such a subjective thing, it hardly seems reasonable to expect there to be.
The one sure tweak is do something about the coupling caps, and take it from there.
Depending on your version of 180 there may be other things, like a different op amp, improved input stage bypassing/supply, filter cap, other caps.. the last I heard people were hoping to get their hands on some ZL caps to try.
The number one biggest thing is ensure it's wired as best it can possibly be, only then is it worth worrying about the little things.
It's pretty well the usual stuff.
Guys it's discussed in this very thread. The coupling caps were shifted around on the 400's, from before, and back to after the op amp. It's not unreasonable to think maxlorenze simply has an oddball.
Henrik Juhl, Hi.
I'm sorry to have to say, no.
Due to constant revisions and improvements, there's no set cookbook to hot rod them, additionally it's such a subjective thing, it hardly seems reasonable to expect there to be.
The one sure tweak is do something about the coupling caps, and take it from there.
Depending on your version of 180 there may be other things, like a different op amp, improved input stage bypassing/supply, filter cap, other caps.. the last I heard people were hoping to get their hands on some ZL caps to try.
The number one biggest thing is ensure it's wired as best it can possibly be, only then is it worth worrying about the little things.
It's pretty well the usual stuff.
needing to start a new thread on the version 6.1 modules
Hi All,
Since there has been a lot of changes on the UCD modules for version 6.1, it might be wise to start a new thread. The ceramic caps at least from what I was told from hypex for decoupling the opamps was changed to a 22 UF cap. I don't know the type it was changed to. So if there are mods to be done on these newer modules, we need to start a new thread to keep everything on an even keel.
Ray
Hi All,
Since there has been a lot of changes on the UCD modules for version 6.1, it might be wise to start a new thread. The ceramic caps at least from what I was told from hypex for decoupling the opamps was changed to a 22 UF cap. I don't know the type it was changed to. So if there are mods to be done on these newer modules, we need to start a new thread to keep everything on an even keel.
Ray
Re: needing to start a new thread on the version 6.1 modules
Hi Ray,
I'd be more in agreement with Roger's first post in this thread "let's try to keep all mods in this thread so they can be found". It makes alot more sense then spreading it all around to more threads people won't want to read or search either.
The change you've mentioned may not yet be implemented in their production modules, however they're done with improved sonics in mind so it should be an extremely interesting module to hear.
Regards,
Chris
ray bronk said:
Hi Ray,
I'd be more in agreement with Roger's first post in this thread "let's try to keep all mods in this thread so they can be found". It makes alot more sense then spreading it all around to more threads people won't want to read or search either.
The change you've mentioned may not yet be implemented in their production modules, however they're done with improved sonics in mind so it should be an extremely interesting module to hear.
Regards,
Chris
A new op amp in the world
I just got samples of a new op amp from National.
It should release very soon. Looks good on paper, by far the lowest distortion amp to date.
Key Specifications
j Power Supply Voltage Range �}2.5V to �}17V
j THD+N (AV = 1, VOUT = 3VRMS, fIN = 1kHz)
RL = 2kĦ 0.000035% (typ)
RL = 600Ħ 0.0001% (typ)
j Input Noise Density 2.7nV/�ãHz (typ)
j Slew Rate �}20V/ƒÊs (typ)
j Gain Bandwidth Product 56MHz (typ)
j Open Loop Gain (RL = 600Ħ) 120dB (typ)
j Input Bias Current 10nA (typ)
j Input Offset Voltage 0.1mV (typ)
Its called an LM4562, and its a dual. Should be interesting.
Don't know when I'll have time though.
Mike
I just got samples of a new op amp from National.
It should release very soon. Looks good on paper, by far the lowest distortion amp to date.
Key Specifications
j Power Supply Voltage Range �}2.5V to �}17V
j THD+N (AV = 1, VOUT = 3VRMS, fIN = 1kHz)
RL = 2kĦ 0.000035% (typ)
RL = 600Ħ 0.0001% (typ)
j Input Noise Density 2.7nV/�ãHz (typ)
j Slew Rate �}20V/ƒÊs (typ)
j Gain Bandwidth Product 56MHz (typ)
j Open Loop Gain (RL = 600Ħ) 120dB (typ)
j Input Bias Current 10nA (typ)
j Input Offset Voltage 0.1mV (typ)
Its called an LM4562, and its a dual. Should be interesting.
Don't know when I'll have time though.
Mike
Re: correct size of Transformer
Ray,
Sorry for the late reply.
I'm thinking two transformers, one for each channel.
One transformer, split secondaries.
I would not share the "ground wire" for each tranny. If you do a dual bridge per tranny, split secondaries, make two floating DC supplies, and then tie the + from one to the - of the other at the UcD you have the ideal solution IMO and others.
As for over voltage. My boards have all 100V caps. Thus they will not be stressed. PS caps I will use will be 80V. If you get over voltage, say 130~140V, what will happen is the UcD will shut down and stop switching. When switching the fets see the voltage accross the supplies (2X65V for example). they are 150V fets. When it shuts down, they see only half that, and no current.
I believe this should be just fine. The down side I see is that if you have very bad line regulation, then the amp will shut down.
The ltspice circuit can show the affect of boosting, which is really minimal. I'd only worry about it if you play records as the amount of boosting is increases as the input frequency drops.
Mike
ray bronk said:
Ray,
Sorry for the late reply.
I'm thinking two transformers, one for each channel.
One transformer, split secondaries.
I would not share the "ground wire" for each tranny. If you do a dual bridge per tranny, split secondaries, make two floating DC supplies, and then tie the + from one to the - of the other at the UcD you have the ideal solution IMO and others.
As for over voltage. My boards have all 100V caps. Thus they will not be stressed. PS caps I will use will be 80V. If you get over voltage, say 130~140V, what will happen is the UcD will shut down and stop switching. When switching the fets see the voltage accross the supplies (2X65V for example). they are 150V fets. When it shuts down, they see only half that, and no current.
I believe this should be just fine. The down side I see is that if you have very bad line regulation, then the amp will shut down.
The ltspice circuit can show the affect of boosting, which is really minimal. I'd only worry about it if you play records as the amount of boosting is increases as the input frequency drops.
Mike
Here my T-NET caps.(ALN20S1067DD) from BHC just mounted in an UCD400 stereo amp. As you can see these caps are rather small in comparison with AL30's. Now the listening.
An externally hosted image should be here but it was not working when we last tested it.
Hi Bert,
Are those the 80V version? Yep, looking forward to hearing about your listening results.
Ray
Are those the 80V version? Yep, looking forward to hearing about your listening results.
Ray
10.000uF/63V, and I will them burn them in 1st. They're fresh from BHC.....well...fresh...date 0605? They don't sell a lot of them probably. They're quit expensive(even sample price, €32,- exl VAT pp ) for such a small sized cap.
1st impression.....there is no magic here........ jet!.They're not worse either. (switching A/B with a standard stereo UCD400 amp. which has a PSU with Vishay 102PHR-ST(4) also 10.000uF/63V).
Rectifiers used(8) MBR20100CT in both amps.
1st impression.....there is no magic here........ jet!.They're not worse either. (switching A/B with a standard stereo UCD400 amp. which has a PSU with Vishay 102PHR-ST(4) also 10.000uF/63V).
Rectifiers used(8) MBR20100CT in both amps.
Cap question
Has anyone looked into the Panasonic T-UP series of 5 lead caps?
These are available from Digikey for around $20 US each. They also are available in 80 volts.
Roger
Has anyone looked into the Panasonic T-UP series of 5 lead caps?
These are available from Digikey for around $20 US each. They also are available in 80 volts.
Roger
Re: Cap question
Looked hard, but not bought yet. I think a friend of mine is going to try them, although he won't have a reference to compare to.
I am going back and forth between those and just popping for the Jensens.
I not being a good DIY'r 🙂
Mike
p.s. National has a really good looking new dual op amp on paper that should release soon.
I want to plug them in as I have some samples. Its better in almost every spec then the AD8610, and its a bipolar input.
Very low bias current and offset too, very workable without coupling caps. LM4562.
sx881663 said:
Looked hard, but not bought yet. I think a friend of mine is going to try them, although he won't have a reference to compare to.
I am going back and forth between those and just popping for the Jensens.
I not being a good DIY'r 🙂
Mike
p.s. National has a really good looking new dual op amp on paper that should release soon.
I want to plug them in as I have some samples. Its better in almost every spec then the AD8610, and its a bipolar input.
Very low bias current and offset too, very workable without coupling caps. LM4562.
Hi Bjt
Do you have a pic of your alumunium mounting plate before assembly, or the underside of it after assembly?
If there's no magic at all I'm confident in saying there's some sort of issue. They don't take too long to break in but the magic is there immediatly.
Any type of wiring diagram should help get it sorted.
Regards,
Chris
PS: I'm about to parallel my Jensen 4 poles with the BHC T-networks.
Do you have a pic of your alumunium mounting plate before assembly, or the underside of it after assembly?
If there's no magic at all I'm confident in saying there's some sort of issue. They don't take too long to break in but the magic is there immediatly.
Any type of wiring diagram should help get it sorted.
Regards,
Chris
PS: I'm about to parallel my Jensen 4 poles with the BHC T-networks.
personal message to T.
Hi t.,
first of all sorry to the mates here, but this is an important question for t.
I am now back in England! I lost your email address, I would ask you some important question.
If you can E-mail me at kephaudio AT yahoo DOT it
By KEPha
Hi t.,
first of all sorry to the mates here, but this is an important question for t.
I am now back in England! I lost your email address, I would ask you some important question.
If you can E-mail me at kephaudio AT yahoo DOT it
By KEPha
Re: Re: Cap question
Nothing about this op-amp on their web site. Wrong ref ?
.
Portlandmike said:
Nothing about this op-amp on their web site. Wrong ref ?
.
classd4sure said:
The toroid is mounted on a L shaped all. bracket. The toroid is than bolted down with a 6mm bolt on the bracket. There is no connection to anything on the top side of the bolt/toroid. So no current flowing through the bolt.
wiring scheme amp.
http://www.grotel.nl/photo/wiring scheme class d stereo.jpg
Re: Re: Re: Cap question
Just not there yet. Its comming, and there are engineering samples that are possible.
I can email a prelim DS if you want one.
Mike
Chris,
Have you pondered wiring your jensens so that the inputs are parallel but the outputs are seperate for each amp?
Mike
stef1777 said:
Just not there yet. Its comming, and there are engineering samples that are possible.
I can email a prelim DS if you want one.
Mike
Chris,
Have you pondered wiring your jensens so that the inputs are parallel but the outputs are seperate for each amp?
Mike
Re: Re: Re: Re: Cap question
Mike,
That and a good half a dozen other ways. In the end I'll go with what's best given the parts that I have, I'll want to keep them // as much as possible, ideally I'd like all current to pass through the slit foil t networks at the output.... i have a little more research /thinking to do in this regard.
Given my required for the slit foil to be last in the signal chain, they'll all likely be in //, though it would be amuzing to try the final BHC in series. More though required. Then I can do less trial and error. I'm sure whatever I end up with will deliver the magic.
Portlandmike said:
Mike,
That and a good half a dozen other ways. In the end I'll go with what's best given the parts that I have, I'll want to keep them // as much as possible, ideally I'd like all current to pass through the slit foil t networks at the output.... i have a little more research /thinking to do in this regard.
Given my required for the slit foil to be last in the signal chain, they'll all likely be in //, though it would be amuzing to try the final BHC in series. More though required. Then I can do less trial and error. I'm sure whatever I end up with will deliver the magic.
Cap question
Mike,
If you read the fine print you will see there is quite some DC resistance internally in these caps using the pins as input/outputs rather than paralleled. Also the ESR goes way up. The solution would be to use a low DC resistance inductor to jumper the current from input to output and not run it through the cap its self. At this point it is getting so messy you would be better off using 2 conventional caps rather than the single Jensen.
No easy solution here.
Roger
Mike,
If you read the fine print you will see there is quite some DC resistance internally in these caps using the pins as input/outputs rather than paralleled. Also the ESR goes way up. The solution would be to use a low DC resistance inductor to jumper the current from input to output and not run it through the cap its self. At this point it is getting so messy you would be better off using 2 conventional caps rather than the single Jensen.
No easy solution here.
Roger
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