And the outside,
The box is macined aluminum. The bottom and front/back are about
4.5mm thick.
I have mounted the trafos on silpads (well, they are the least efficient).
Since I had to rewind the trafos I never put the mylar tape on the secondary-ambient
back on. So they should sissipate some heat to the bottom.
Also I did not have time to make supply boards so I used experimental
boards which I reinforced with desolder-wire where necessary.
/ Mattias
The box is macined aluminum. The bottom and front/back are about
4.5mm thick.
I have mounted the trafos on silpads (well, they are the least efficient).
Since I had to rewind the trafos I never put the mylar tape on the secondary-ambient
back on. So they should sissipate some heat to the bottom.
Also I did not have time to make supply boards so I used experimental
boards which I reinforced with desolder-wire where necessary.
/ Mattias
Attachments
That's actually a cool cover, until someone spills their drink on it.
I'd recommend finishing off that top edge with some sort of trim, you'll thank yourself for having done it when someone's shirt doesn't get caught in it and pulls the sucker down.
I'd recommend finishing off that top edge with some sort of trim, you'll thank yourself for having done it when someone's shirt doesn't get caught in it and pulls the sucker down.
Hi,
Thanks 4 the replies.
The red was some leftover from my RC model boat and I think it is cool.
Usually I always use Bruel & Kjaer green, which is a bit "Instrumentation".
The amp will not sit on the record player so no one will spill anything
on it.
But you are right, I don´t need the ventholes and to keep dust out I might
just change the top. The amplifier was finnished in panic like 1:30 in the
morning for my friends wedding in the evening the same day.
It was driving a pair of JBL PA/Studio speakers with 15" in the bottom.
Did we play loud?...Yes we did! (100+dB/W SPL)
/ Mattias
Thanks 4 the replies.
The red was some leftover from my RC model boat and I think it is cool.
Usually I always use Bruel & Kjaer green, which is a bit "Instrumentation".
The amp will not sit on the record player so no one will spill anything
on it.
But you are right, I don´t need the ventholes and to keep dust out I might
just change the top. The amplifier was finnished in panic like 1:30 in the
morning for my friends wedding in the evening the same day.
It was driving a pair of JBL PA/Studio speakers with 15" in the bottom.
Did we play loud?...Yes we did! (100+dB/W SPL)
/ Mattias
Your UCD180 amplifier
I notice that those are honkin' speaker cables ... type? ... DIY?
Also I believe that those are "unbalanced" RCA input type ... yes?
I notice that those are honkin' speaker cables ... type? ... DIY?
Also I believe that those are "unbalanced" RCA input type ... yes?
Hi,
The speaker cables on the pictures are way to thin, about 0.5mm2.
I will use at least 1.5mm2.
The speaker connectors are isolated High current/voltage type banana
jacks on the amp. On the cable I just put Wago type banana plugs.
I used banana plugs for simplicity and thats what I had at home.
The input connector is a 3pin DIN type connector often used for microphones
when XLRs are not used. I didn´t have space left for the XLRs.
I wanted to use the Neutrik XLR/Tele combo but that guy extends even
further into the case than the standard XLR.
/ Mattias
The speaker cables on the pictures are way to thin, about 0.5mm2.
I will use at least 1.5mm2.
The speaker connectors are isolated High current/voltage type banana
jacks on the amp. On the cable I just put Wago type banana plugs.
I used banana plugs for simplicity and thats what I had at home.
The input connector is a 3pin DIN type connector often used for microphones
when XLRs are not used. I didn´t have space left for the XLRs.
I wanted to use the Neutrik XLR/Tele combo but that guy extends even
further into the case than the standard XLR.
/ Mattias
aside / Q & A
Assuming you were able to use the Neutrik XLR/Tele combo ( ?? http://www.neutrik.com/content/Products/products_group.asp?level2id=204_57051 ??), how would you wire it up??
I'm looking for a relatively standard, reproducable way to do this connection for both balanced and unbalanced amplifiers and pre-amps ... a serious DIY project that may go to production.
Thanks
Assuming you were able to use the Neutrik XLR/Tele combo ( ?? http://www.neutrik.com/content/Products/products_group.asp?level2id=204_57051 ??), how would you wire it up??
I'm looking for a relatively standard, reproducable way to do this connection for both balanced and unbalanced amplifiers and pre-amps ... a serious DIY project that may go to production.
Thanks
Eddy,
How to wire the XLRs and teleplugs are standardised. Also if you use
2 pole teleplug, you dont have the ring on the connector, it will work
on a balaced input since the negative signal will be grounded.
But it is best to make the unbalanced part at the sending end and use
balanced cable/connection to the amp letting all common mode noise
picked up by the cable be suppressed at the balanced inputstage of
the amp.
The Neutrik connector have separate terminals for the XLR part and the
teleplug part that you can solder wires to or get the PCB mounted one.
Please see the attached pdf from RANE it is very good reading as are all
of their technotes, at least to me.
I take the liberty to post it here.
/ Mattias
How to wire the XLRs and teleplugs are standardised. Also if you use
2 pole teleplug, you dont have the ring on the connector, it will work
on a balaced input since the negative signal will be grounded.
But it is best to make the unbalanced part at the sending end and use
balanced cable/connection to the amp letting all common mode noise
picked up by the cable be suppressed at the balanced inputstage of
the amp.
The Neutrik connector have separate terminals for the XLR part and the
teleplug part that you can solder wires to or get the PCB mounted one.
Please see the attached pdf from RANE it is very good reading as are all
of their technotes, at least to me.
I take the liberty to post it here.
/ Mattias
" ... if you use 2 pole teleplug, you dont have the ring on the connector, it will work on a balaced input since the negative signal will be grounded. But it is best to make the unbalanced part at the sending end and use balanced cable/connection to the amp letting all common mode noise picked up by the cable be suppressed at the balanced inputstage of the amp. ..."
Yes, I knew that ... The idea for our setup is to maintain a balanced line between both, pre-amp and amp with the option of going to unbalanced lines ... the ground being unconnected to signal lines at either end. I suppose I will have to go with an active circuit, rather than passive, to get this job done ... with a switch to revert to unbalanced on the amp end as the need arrises ...
The method you describe is SOP, but I was just searching for alternates = trying to get the best results possible.
Thanks ... and fine device you have made.
Yes, I knew that ... The idea for our setup is to maintain a balanced line between both, pre-amp and amp with the option of going to unbalanced lines ... the ground being unconnected to signal lines at either end. I suppose I will have to go with an active circuit, rather than passive, to get this job done ... with a switch to revert to unbalanced on the amp end as the need arrises ...
The method you describe is SOP, but I was just searching for alternates = trying to get the best results possible.
Thanks ... and fine device you have made.
OK I see,
I suppose a switch or some clever circuit do the job.
So far I have only tested my UCD amp fully balanced from preamp
to the UCD amps input. I just tied the UCD signal GND to pin 1 of the
input connector and directly from pin one to chassis at the connector fastening screw.
So it remains to be seen if the amp is still dead quiet when driven unbalanced.
/ Mattias
I suppose a switch or some clever circuit do the job.
So far I have only tested my UCD amp fully balanced from preamp
to the UCD amps input. I just tied the UCD signal GND to pin 1 of the
input connector and directly from pin one to chassis at the connector fastening screw.
So it remains to be seen if the amp is still dead quiet when driven unbalanced.
/ Mattias
balanced to unbalanced ...
FYI: The usual procedure here in North America for Computer wire shielding is to tie the ground line and shield at the "head end", upstream toward the host computer. (Examples: USB, FireWire, shielded EtherNet, etc.)
Generally accepted practice for pro-audio (Standard Operating Procedures = SOP) is to tie the ground or shield to the device with the largest ground plane, usually the amplifier. (In radio, this would of course be tied to the transmitter.)
FYI: The usual procedure here in North America for Computer wire shielding is to tie the ground line and shield at the "head end", upstream toward the host computer. (Examples: USB, FireWire, shielded EtherNet, etc.)
Generally accepted practice for pro-audio (Standard Operating Procedures = SOP) is to tie the ground or shield to the device with the largest ground plane, usually the amplifier. (In radio, this would of course be tied to the transmitter.)
Beautiful amp.
I am curious about the four trannies (transfos). If you used 2 it would be sufficient for two separate supplies giving dual-mono operation. Why and how do you use 4 trannies? Is it two 110v-primaries trannies mounted in series? Can you share the schematics?
Guy
I am curious about the four trannies (transfos). If you used 2 it would be sufficient for two separate supplies giving dual-mono operation. Why and how do you use 4 trannies? Is it two 110v-primaries trannies mounted in series? Can you share the schematics?
Guy
hi Guy,
There are 4 transformers for the following reasons.
Thats what I had in stock with the max height allowed by the box, which I really wanted to get some use of.
And also they were single output voltage and about 80VA a piece meaning I didn't want to add another secondary.
I did however remove some turns to not exceed the UCD max voltage
at no load and highest line voltage.
The transformers are paralleled on the primary and the secondaries are
series connected by the pair. The big caps are 10mF, 63V each.
Each channel has its own power supply only charing the mains EMI filter.
Unfortunately there is no schematic.
/ Mattias
There are 4 transformers for the following reasons.
Thats what I had in stock with the max height allowed by the box, which I really wanted to get some use of.
And also they were single output voltage and about 80VA a piece meaning I didn't want to add another secondary.
I did however remove some turns to not exceed the UCD max voltage
at no load and highest line voltage.
The transformers are paralleled on the primary and the secondaries are
series connected by the pair. The big caps are 10mF, 63V each.
Each channel has its own power supply only charing the mains EMI filter.
Unfortunately there is no schematic.
/ Mattias
Thanks, for the explanation. Thats a good way to get dual voltage.
BTW I recall that Bruno Putzeys (the UcD inventor) prefers no EMI filters on the mains saying that the UcD does not generate noise and that the filters have some adverse effects related to grounding (I don't remember exactly how and why).
Guy
BTW I recall that Bruno Putzeys (the UcD inventor) prefers no EMI filters on the mains saying that the UcD does not generate noise and that the filters have some adverse effects related to grounding (I don't remember exactly how and why).
Guy
Guy,
It has become a habit to use input filtering. I put it there to keep mains coducted
noise from entering the amp.
And yes, sometimes the Y-caps going from line to GND can cause trouble.
Specially if the unit was to be connected to a non earthed outlet.
/Mattias
It has become a habit to use input filtering. I put it there to keep mains coducted
noise from entering the amp.
And yes, sometimes the Y-caps going from line to GND can cause trouble.
Specially if the unit was to be connected to a non earthed outlet.
/Mattias
Wow, I wish I had see this before I stuffed my box. You did such a nice clean job! I started clean but soon the wiring got out of hand.
I have to agree though with your sonic results of these UCD180. They have a nice good clean sound. I am really impressed. I breadboarded on a table and learned a few things. it at first and had a little hum but routed and grounded things better and I am very happy with virtual if not complete silence.
The chassis and PS ground are tied through a RC filter. Epcos B41550 capacitors, Intl Rec 16CTU04 diodes. So far no UCD mods but I will have to investigate the hotrod section. I still have to add a soft start. Next time I will go with better transformers. Those 500W Avel have a bit of physical hum but I don't notice it now that they are in the box.
It shames the 300B in many respects. It is far more quiet, less siblance, tighter bass. Not as warm but still very nice. Not too sterile. Much better than the old NAD.
I have to agree though with your sonic results of these UCD180. They have a nice good clean sound. I am really impressed. I breadboarded on a table and learned a few things. it at first and had a little hum but routed and grounded things better and I am very happy with virtual if not complete silence.
The chassis and PS ground are tied through a RC filter. Epcos B41550 capacitors, Intl Rec 16CTU04 diodes. So far no UCD mods but I will have to investigate the hotrod section. I still have to add a soft start. Next time I will go with better transformers. Those 500W Avel have a bit of physical hum but I don't notice it now that they are in the box.
It shames the 300B in many respects. It is far more quiet, less siblance, tighter bass. Not as warm but still very nice. Not too sterile. Much better than the old NAD.
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