UCD180 questions

[Jan-Peter]

Thomas,

The price is as follows;
2. High Grade designed for the Audiophile with the following specs,
- BHC Slitfoil series 4 x 10.000uF / 63V
- Stereo DC protection, with relais.
- Fast recovery rectifier with small capacitors to remove switching noise.
- Fuse protection.
- Small 2 x 12V powers supply for a preamp. Audiophile designed.
- Suitable for a 4 x UcD180 or Stereo UcD400. (In a 5+1 setup you can use only two)
Price EUR 165.00

Transformer 160VA: 230V / 2 x 27V - EUR 30.00
Suitable for a Stereo UcD180

Transformer 500VA: 2 x 115 / 2 x 42V / 2 x 16V - EUR 65.00
Suitable for a Stereo UcD400

All prices are ex. works, ex. VAT.

Delivertime Power supplies:
Standard version +/-2 weeks.
High Grade version +/-4 weeks.
Transformers are on stock

Jan-Peter

 

[Thomas B]

Hi Jan-Peter,

Do you think it is overkill to use one high grade power supply only per ucd180 module?

I plan to build four monoblocks, each main component sitting on copper plates, resting on compression springs for vibration isolation. When I suspended the modules only of my current 4 channel ucd180 amp, the sound opened up in ways almost too good to be true.

/Thomas B

 

[ghemink]

Hi Jan-Peter,

Do you think it is overkill to use one high grade power supply only per ucd180 module?

I plan to build four monoblocks, each main component sitting on copper plates, resting on compression springs for vibration isolation. When I suspended the modules only of my current 4 channel ucd180 amp, the sound opened up in ways almost too good to be true.

/Thomas B

If you go this far, then why don`t you use UcD400 modules? They are supposed to be a bit better.

Gertjan

 

[Thomas B]

Hi Gertjan,

How much better? If ucd400 is substancially better than ucd180, then you have a point. I think Jan-Peter stated that the sonics are the same between modules though. I don't need the extra power as my active 2way WLM Aura speakers have a sensitivity of 98 dB. Also I hear that Hypex is planning an audiophile ucd module... Perhaps someone could elaborate on this rumour?

BTW; does anyone know the dimensions of the Hypex high grade power supply?

 

[Yves Smolders]

Jan-Peter,

when released, can you post a simple connection schematic like you have for the UcD modules?

It's nice to know what connections/placement have to be considered.

I'm also figuring out how to connect 2 transformers to a single bridge rectifier - I've seen the schematics with 2 bridges but want to be sure how to do it on a single one.

 

[richie00boy]

Just join the start of one winding to the finish of the other one, this is your common 0V point then, and the outer wires are your AC lines to the bridge.

I think you would be wise to use 2 bridges though as you can get a better quality 0V that way and also load your transformers nicer.

 

[Bruno Putzeys]

I think Jan-Peter stated that the sonics are the same between modules though.

By design, yes, but in the end some passives (mainly the 470uF electrolytics) were changed to accommodate for the higher voltage. The caps on the 400 turned out to sound quite a bit better than the ones used on the 180.

Also I hear that Hypex is planning an audiophile ucd module... Perhaps someone could elaborate on this rumour?

The next module is a 700W design. We have no plans to add explicitly audiophile modules to our portfolio for economic reasons (they'd only sell to the diy community and subsequently no more to industrial audiophile customers - it makes little sense to create competition for one's own customers!). That said, audiophile UcD designs are not radically different from the standard circuit, differing largely only in component choice. Anyone with a steady hand, good ears and a collection of different-sounding (but otherwise functionally compatible) parts can modify a standard module to suit their own sonic tastes. I'm surprised so few people are hot-rodding their UcD's.

 

[peranders]

I'm surprised so few people are hot-rodding their UcD's.

Maybe you have done a good job here, no need for modding.🙂

 

[PHEONIX]

Hot- Rodding the UCD

Maybe you have done a good job here, no need for modding.🙂

The job that has been done on the UCD 180 and UCD400 is good as a starting point but they are hardly the last word in absolute performance obtainable from these modules, where is the DIY challenge in putting a module in a box and connecting a power supply to it , and then patting your self on the back for building a good amp.


Regards
Arthur

 

[Bgt]

By design, yes, but in the end some passives (mainly the 470uF electrolytics) were changed to accommodate for the higher voltage. The caps on the 400 turned out to sound quite a bit better than the ones used on the 180.

Bruno, any id what cap. to use since a low ESR cap. was not recommended on your 400 thread.
On my 180's are the blue Vishay/BC caps used.
What brand are the caps used on the 400?

 

[ghemink]

Bruno, any id what cap. to use since a low ESR cap. was not recommended on your 400 thread.
On my 180's are the blue Vishay/BC caps used.
What brand are the caps used on the 400?

Yes, that would be my question too. That would help many DIYers.

Hot-rodding the UcD180 (and 400) is not that easy. I think most people don't want to mess with the parts in the switching power stage. You can't mod anything on the UcD PcB (the small encapsulated module), so what is left is replacing and or adding some caps and the input opamps. I replaced some caps with BG caps, sounds good but I have not done any before/after comparison.

I also noticed that after several months the sound became even better. Which could be real or suggestion, just getting used to the sound???

I now have also UcD400 AD8620 modules, have not hooked them up yet, would be interesting to hear how they sound in comparison with UcD180.

Best regards

Gertjan

 

[Bruno Putzeys]

Bruno, any id what cap. to use since a low ESR cap. was not recommended on your 400 thread.
On my 180's are the blue Vishay/BC caps used.
What brand are the caps used on the 400?

They're Yageo, standard type.

 

[Bruno Putzeys]

Hot-rodding the UcD180 (and 400) is not that easy. I think most people don't want to mess with the parts in the switching power stage. You can't mod anything on the UcD PcB (the small encapsulated module), so what is left is replacing and or adding some caps and the input opamps.

Well, most of the fun, sonically speaking, is in the caps. There isn't much on the modulator PCB you can do to improve the sound. I use the same circuit for all my amps, including the most exotic ones.

The 2 large elcaps and the output film cap are the prime candidates for tweaking (unfortunately you can't use larger MKP's for the output cap. Any replacement should fit in the alotted space and be mounted flush to the PCB, to prevent stray inductance).

 

[ghemink]

Well, most of the fun, sonically speaking, is in the caps. There isn't much on the modulator PCB you can do to improve the sound. I use the same circuit for all my amps, including the most exotic ones.

The 2 large elcaps and the output film cap are the prime candidates for tweaking (unfortunately you can't use larger MKP's for the output cap. Any replacement should fit in the alotted space and be mounted flush to the PCB, to prevent stray inductance).

Hi Bruno,

Thanks for the advice. Probably this will cause a whole round of new tweaking results 🙂

About the 2 large caps. Are the results measurable?

I was thinking of the following measurement.

1. supply a square wave to the UcD inputs (say 1kHz) and output for example half power in a 4 or 8 Ohm dummy load
2. measure the rail voltage over the elcaps using a scope that is triggered on the square wave on the input

What I plan to see with that is:

1. Voltage drop due to the positive or negative rail output Mosfet switching on
2. Possible high frequency ringing on the rail

From an engineering point of view, the best cap would give the least voltage drop, asking for a cap with low series resistance and inductance. However, that could cause high frequency ringing which is also considered not desired.

Since the drop is probably not very large, the scope should most likely be AC coupled so that a more sentive measurement range can be selected.

Any comments on the above measurement method or any other suggestions.

Best regards

Gertjan

 

[Bruno Putzeys]

Annoyingly, things that matter to the sound, while often measurable, go hidden among a bunch of other equally measurable effects that do not matter very much.

The most interesting look at capacitor performance in this circuit comes from the switching alone - no need to modulate the amplifier. Looking at the rail you will see things change when you change caps (amplitude of the ripple, any ringing? etc).

You will find that certain things do correlate well with the listening results, but that often you'll hear things that are not at all obviously linked to visible changes.

 

[Pasi P]

Bruno,

I think many of us are interested to tweak something but..
Discussion about changing caps etc. are around here but to beginner like me it is not clear what caps are wich and what is the good alternative caps to try. I do not want to change worse part to well working amp.

So, if it is possible to you to say good replacing capacitor types and also show location for that. Simple instructions for simple people 😉
It will help a lot.

Thank you.

 

[Bruno Putzeys]

So, if it is possible to you to say good replacing capacitor types and also show location for that. Simple instructions for simple people 😉

I understand what you mean, but I find it is more productive when I give general hints about where to look, not what to find. I have quite a bit of interesting things to say about class D amplifiers, but I'm not the kind of person to work through large numbers of different components in long drawn-out listening sessions. There are certainly other people here who have much more interesting things to say about component choice, simply because they have the patience of trying out a larger gamut.

Now that I've indicated that the capacitors are fair game for tweaking, members will start reporting which caps or combinations work well for them. Otherwise put, the instructions you're looking for will appear in due time and I won't have to write them. On top of that, I'm quite sure I'll learn about some component variants that I never came across.

 

[SEIJI]

Capacitance

Hi Bruno,

I am about to build a power supply for 6 module of UCD180 that will drive a multiway horn speaker system via digital electronic crossover, I have only one question to ask, In you profesional view, what in the right amount of capacitance to serve the 6 module of UCD180 via double bridge 500VA transformer. I would like to try some BlackGate, Elna Cerafine & Nichicon GoldTune.

Many thanks for your kindness and help.

I also had two module of UCD400 to be build after the multichannel UCD180.

 

[stef1777]

Hi Folks!

I've started a new UcD180 project. This time a five channels amp to replace my UcD180 mono block.

I have a large stock of rectifiers of regular MUR1520 and MBR10100 Schottky's. The MUR1520 are rated for 15A 200V and the MBR10100 for 10A 100V. The transformer will be a 2 x 30V, 300VA.

My plan is to use 4 MUR1520 + snubber caps across the diodes per transformer wiring.

OR

4 MBR1100 without snubber caps across the diodes per transformer wiring.

Difficult choice!

What to you think of each solution?

 

[maxlorenz]

"I'm surprised so few people are hot-rodding their UcD's."

The problem is that many of us don't know how to solder/desolder SMD components! (I'm talking about input opamps) But wait until we learn! 😉