Paradise Builders

[slav]

I had also used half the total mF at the emitters and deleted their bypasses. For earlier subsonic roll-off.

At what freq. does your Paradise cut off with these changes?

 

[slav]

It was measuring 62dB on mine (Rev2 PCB). My RIAA values twist was http://www.diyaudio.com/forums/analogue-source/218625-paradise-builders-199.html#post3438188

Link takes me to the last page of the thread , I found your values in the manual: 12nF, 34.7nF, 9.1k, 67.8k , are these correct?
Looks like you're cutting bit of LF and HF , I listened last weekend to Paradise and it seems to over emphasise a bit HF in my system your values might be a way to go .

 

[Salas]

Link works on me, so here is my old post's text:

"Miib tuning has a bit more treble and bass. +0.4db HF +0.2dB LF in my build by measurement. Add 1nF to the treble caps C2a, C2b and parallel 820k-1Meg to R9a R9b. Matter of tolerances. You are looking for 67.8k net. That way it goes near neutral so you can have an alternative listening session. Its a matter of taste and system integration mainly."

 

[Salas]

At what freq. does your Paradise cut off with these changes?

Look

 

[AndrewT]

Link takes me to the last page of the thread ,..............

Salas post4095 link takes me to post3691

 

[slav]

Salas post4095 link takes me to post3691

Must be Chrome playing tricks on me , checked with Microsoft Edge and it takes me to the said post , thanks

 

[Salas]

Takes me to correct #1982

Until Jason will take the forum to a new platform there are various buggy things going on with browsers it seems. I have copied the original post's text four posts above anyway.

That makes for 33n3 12n 9k1 67k8

 

[slav]

Takes me to correct #1982

Until Jason will take the forum to a new platform there are various buggy things going on with browsers it seems. I have copied the original post's text four posts above anyway.

That makes for 33n3 12n 9k1 67k8

Thank you

 

[slav]

Question about grounding , there is a diagram in assembly guide showing Paradise grounding ,
mains ground seems to be connected to the chassis via DDCR network is that correct?

 

[sq225917]

yup, with another 10r to common. I've never found it necessary in either 2, 3, or 4 box builds.

 

[slav]

I' thinking about something like , mains ground going to the chassis of PSU unit (star point) , both DC supplies ( 2 transformer build) going to the star point via 10R resistor, both RIAA chassis connected to the star via 10R , tonearm ground connected to one of the RIAA chassis via 10R

 

[sq225917]

Sounds fair. I like to float the signal gnd and not connect it to chassis gnd at the RCA sockets.

I'm sure you'll fiddle about a bit to find the quietest solution.

 

[FdW]

And I think it is good to keep the capacitor and diodes, the first to ground HF, the second for safety The resistor is to break any possible ground loop, so, do not worry to much about ground loops.

 

[slav]

What type of diodes would you recommend , couldn't find anything on the diagram.

 

[FdW]

Most of the time I'm using something like a 1n4007

But this S2K100-5000 or 1N5404RLG would be better (or most DO201's 400V or higher max surge current 100A or higher will fit the job).

At worst the diode should survive a mains short over the diode (to be absolutely safe).

 

[slav]

I'll give it a go , thank you

 

[kamis]

I have a few unused LT1010 TO-220 buffers which left from another project. What about using them as a alternative Paradise buffer?

 

[ste]

Finally getting around to building up my Paradise boards and have a quick question about matching.
I've done a first sift on a Peak DCA 75 (the one that does curves) and I'd now like a good match on the input transistors.
Each of these, I understand, operates at around 3.5mV, but on the tester you need to specify the Vce as well. Any ideas as to what to input here? It's a bit of an issue as hfe is pretty flat with the npn's as Vce rises, but hfe with the pnp's rises quite a bit with Vce.
Thanks in advance.

 

[hesener]

Hi ste, the input transistors are running at 3mA each, in the circuit the VCE is around 14V. The DCA75 can be set from 3V...9V, so I would go for 9V. Most important is that all mesure the same, the VCE is not so important.

 

[avinunca]

OPA2140

We have being talking about a low cost alternative to the OPA627 as a servo.
There is a new precission Fet Opamp from BB :
http://www.ti.com/lit/ds/symlink/opa2140.pdf
This one really has great DC specs, very low distortion, low noise and a wide PSU voltage range.
Needs a DIL adapter though to be used in the Paradise.
I have not tried it so far. Even for me as an opamp neard it is hard to catch up whats new and usefull.

Has anyone used the OPA2140? Is it as good as the OPA627?

If not as good, should I use OPA627AP or BP?

OPA2140AID | Texas Instruments OPA2140AID, Dual JFET Op Amp, RRO, 11MHz, 4.5 → 36 V, 8-Pin SOIC | Texas Instruments

Thanks