Any news on UCD700?

[Lars Clausen]

I expect it's impressions you want and not measurements

Thanks Chris, your interest is noted.

It shouldn't be up to me, and what i want. Maybe we can do this as a kind of 'open source' project, and let us discuss here on the forum, what kind of test we want, or even let it up to the testers.

What do you all think?

 

[classd4sure]

Thanks Chris, your interest is noted.

It shouldn't be up to me, and what i want. Maybe we can do this as a kind of 'open source' project, and let us discuss here on the forum, what kind of test we want, or even let it up to the testers.

What do you all think?

Why limit it to three? Make up a list of those either party is ok with, make it's own shoot-off thread, let each one try it a month.

The only tests required is obvious enough, meaningful ones. I myself could can't yet do those, the sound card is ok for the job but the interface isn't yet there.

So people should keep that in mind. I hope we're not out to prove that someone doesn't have the measurements which they claim though, and such measurements should come from the manufacturer directly, on the same equipment they've taken any other measurement. Everyone's test equipment will have some variance it will get old seeing after awhile.

Regards,
Chris

 

[Jan-Peter]

Originally posted by Yves;
OK, that was the way I was thinking to do it, but was afraid this solution is "too easy" - maybe more parts than the opamp need power, and I'm wondering if the GND to the opamp and the GND of the amp's power need to be connected in some way (common ground thing)

It's not that i'm too lazy to find out, i'm just too scared to do something wrong and waste a module that is quite expensive to my taste.

It's indeed very easy, remove the two regulators (BDX33/34C). Solder on the emittor pad of the BDX33C +12V, and on the emittor pad of the BDX34C -12V. Thereby for the best sonic performance (we have found out) you have to connect the low power ground and high power ground at the UcD module. So remove the ground connection from the low power to the high power at the High Grade power supply.

This is an interesting mod.... However I have to officially announce that we can't give guarantee on modded modules.

Regards,

Jan-Peter

 

[Lars Clausen]

I am thinking more in the line of listening tests, and over-all impression etc.

Jan-Peter: what is your opinion about letting 3 independent teams do this A/B test?

 

[Yves Smolders]

Indeed, an opamp does not need a GND connection, so it basically has a + and - supply pin, a + and - input and an output, 5 pins, that's it. The other 3 pins are often not connected internally, some opamps use additional pins for offset compensation and other features.

Sorry for continued thread hijacking, just ignore

Yeah I think I figured it out from some other sites thanks!

@Lars,

I've got a good speaker setup to do your tests, but don't have the means to do double blind testing. Any other tests might be biased

@JP,

Thanks for the detailed methods! Noted that this voids warranty! Your support to the DIY (and DIY-challenged/impaired like me ) is truly great!

 

[hpsxr]

more and more questions

Jan-Peter,

In the datasheet of the "UcD700 HG PS" you have the following specifications:
Output Power: 600Watt and AC input voltage: Typical 2 x 46 Vac

If the UcD700 can give 900W (in 3 Ohms) with the recommended working voltage of 90VDC, the AC input voltage will
be something beetween 63-65VAC.

The "UcD700 HG PS" will limit the available max. power of UcD700 (the limitation comes from rectifiers and fuses?) !

The rectification and regulation of the "15V driver voltage for the power FET's" is in the UcD700 module (after J13) ?
Can you give details about this auxilliary AC-supply (something like 15VAC/50mA) ?

ps- the Hypex SoftStart isn't up to the task with the 1200VA of the stereo transformer.


Thank's
Hugo

 

[Jan-Peter]

Hugo,

The link to the UcD700 HG PS, is wrong. We have now removed it. The datasheet is still in progress. But on the page with the picture is written the most importend data.

The "UcD700 HG PS" will limit the available max. power of UcD700 (the limitation comes from rectifiers and fuses?) !

The fuses will be 10A, and the rectifiers can handle even more current, so the UcD700 is still the limitation.....

the Hypex SoftStart isn't up to the task with the 1200VA of the stereo transformer.

The softstart module can handle our 1200VA transformer.

Regards,

Jan-Peter

 

[lawbadman]

Hey Jan-Peter or Bruno,
Why did you use BHC capacitors for the HG power supply, why not Rifa, Elna or computer grade Cornell Dubilier?

Is it to save money or do they sound better?



Thanks
Lawrence

 

[Jan-Peter]

We have reviewed; BCC / Mundorf / BHC-Slitfoil / Black Gate, and a lot of others.

Without any doubt, the BG were the best! But too costly, the second are the BHC-Slitfoil. So we choose for the BHC-Slitfoil.

It can be that other brands will also sound ok, we did not yet tested them.

But for the moment we are VERY happy with the BHC-Slitfoil, it's not only the sonic performance, the rest of the quality is also very good.

Regards,

Jan-Peter

 

[Kevin Haskins]

I'm going to use a pair of the DACT power supplies on the opamps and I'd be happy to post my subjective impressions of the modification.

In terms of listening test and such I'd be happy to arrange a controlled test at a DIY event. We could do a blind test between a couple configurations with a test group of people.

Lars, if you want to send us your newest design I'd be happy to provide for an unbiased test group and a valid comparison with a couple different speaker loads.

 

[Stanray]

Applying for the test team. I’m in search for high quality amps for my Apogee Scintillas. These are completely rebuilt 1 ohm versions with new bass membranes, mid-high ribbons, high end filter components and silver wiring. They need current as well as finesse

 

[Yves Smolders]

I think everyone here would like to apply...

I have a pair of B&W Nautilus 804 and a pair of Nautilus 805's to test with.

I already have stereo UcD400 power in a "test setup", but this will change to a full hypex setup soon.

The 804 are not exceptionally difficult to drive (except for bass maybe, the have a nasty impendance curve in bass region) but are very revealing for midrange (female voices), have incredible staging and have ear piercing highs when they don't get the right "juice"

However, I'm not sure how I would be able to do blind A/B tests - I could only judge "from the heart" and most of the time that would be wrong.

 

[Jan-Peter]

Hello,

We are not interested for a test by different teams of the Zappulse versus UcD modules. This has already be done several times in the past, besides this there have been very often discussion (heavy discussions!) between these two different amps. We don't wants to start this again.

BUT, everbody is of course free to post their own experience between these two products.

We are all looking forward when the UcD700 will be on stock

Cheers,

Jan-Peter

 

[Jan-Peter]

Hello,

Prices of the UcD700; I have to correct myself, in the protos we have used some standard 220uF / 100V capacitors. Because of the performance level of these new UcD amplifier, we only like to go for the best what is available. So we will implement the Vishay / BCC 135 (or the newer 136) Low Impedance 105oC capacitor. The price of these capacitors are much higher as the standard stuff, so……..;

The price of the UcD700ST will go to EUR 225.00 and with the AD upgrade to EUR 255.00. (ex. VAT)

I was in my first post about the prices a little bit too, sorry for this inconvenience....

----------------------------------------------------------------------------------------------------
More technical info;
- input capacitors can be bypassed with a simple jumper.
- It’s now possible to remove the op amp buffer stage for upgrading to a dual single op amp (OPA637????)
- On the modulator we have add a DC offset potentiometer, to adjust the DC offset to <1mV. Interesting if you bypass the coupling capacitors….
- Now all 220uF / 100V capacitors Low Impedance Vishay / BCC135 (or the newer 136)
- there is a lot of space to change the standard 3x330nF output capacitor to other exotic types. Actually you can even place 5 capacitors in parallel (5x180 or 220nF instead of 3x330nF).

Cheers,

Jan-Peter

 

[Lars Clausen]

So we will implement the Vishay / BCC 135 (or the newer 136) Low Impedance 105oC capacitor. The price of these capacitors are much higher as the standard stuff, so……..;

A very good choice!

Where did you come across this idea Jan-Peter?

 

[peranders]

Lars, if you want to send us your newest design I'd be happy to provide for an unbiased test group ....

Is it possible to be unbiased?

 

[Jan-Peter]

Bruno mailed me already 1,5 year ago to use the Philips / BCC 135 in the UcD700.....

BTW how did you come on the name 700XI...

Cheers,

Jan-Peter

 

[Kevin Haskins]

Is it possible to be unbiased?

As an individual.... no. We can certainly operate with a test group of individuals for whom their bias is unknown. ;-)

I'd only propose that we have two amps which we could slip in and out of the system without a random group of Pacific Northwest DIYers knowing which amplifier was playing at a given time. We can make up a small score card and room for subjective comments on both amps. I'm unwilling to get rigorous enough to calculate standard deviations with the test group but we could get a seat of the pants feeling for how big the differences where between two amplifiers.

 

[Kevin Haskins]

Hello,

We are not interested for a test by different teams of the Zappulse versus UcD modules. This has already be done several times in the past, besides this there have been very often discussion (heavy discussions!) between these two different amps. We don't wants to start this again.


Jan-Peter

Debate is often not pleasant but it's the mechanism that forums thrive on.

It's important to feed the beast of public opinion from time-to-time anyway.

 

[ghemink]

Hello,

Prices of the UcD700; I have to correct myself, in the protos we have used some standard 220uF / 100V capacitors. Because of the performance level of these new UcD amplifier, we only like to go for the best what is available. So we will implement the Vishay / BCC 135 (or the newer 136) Low Impedance 105oC capacitor. The price of these capacitors are much higher as the standard stuff, so�E..;
........

Cheers,

Jan-Peter

I guess other low impedance caps could perform in that position as well? For example Panasonic FC? Actually was thinking of putting either BCC136 or Panasonic FC caps on my UcD400 modules, possibly 100V versions as these have slightly lower impedance. I want to take a look at the switching waveforms when caps are changed, anybody done that?

Best regards

Gertjan