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Minidsp Flex Eight!

Paul Ebert

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Did you verify the cable after building it? Especially RCA sleeve is not tied to both pins 1&3 XLR?
Yes, I verified that the pin of the RCA is connected to pin 2 (only) of the XLR and that the sleeve of the RCA is only connected to pin 3 or the XLR.
 

TabCam

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I finally got around to building a cable and being able to try it. I'm getting hum that's about as loud as the signal. I made the cable using this diagram:
This is configuration 17 from the Rane link, which seems correct to me.

Any suggestions?

View attachment 291647
There are unfortunately various ways to connect RCA to XLR. Here a topic that starts with discussion those various options. The Hypex link is't up to date but the Hypex legacy pin 1 problem white paper shows a different way of implementing RCA to XLR with a RC network that your version doesn't use. He describes the option that solved his ground loop In this post with a few other suggestions after that post.
 

howard416

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Anyone know if this device uses an R/C/D network (or ground loop breaker) to avoid ground loops? And whether the RCA shells are isolated from chassis?

Also, does it suffer from the same IMD issue that hurt the multi-tone performance of the Flex, as measured previously by Amir?
 
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McFly

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I finally got around to building a cable and being able to try it. I'm getting hum that's about as loud as the signal. I made the cable using this diagram:
This is configuration 17 from the Rane link, which seems correct to me.

Any suggestions?

View attachment 291647
Did you try like this

1689196172618.png
 

MCH

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hi!
can someone share a detailed picture of the internals? i am mostly interested on the output stage. Thanks!
(edit: no longer necessary. Would be still curious to see it though)
 
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MCH

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thanks @JSmith , i know those ones, i am interested in this part below. Those pics (the only ones i know, btw) are not sharp enough to identify those components

1695475433133.png
 

muehleisen

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@MCH andI too am interested in the output section. Thank you @JSmith for the pictures! I see the OP1678 in first picture, but there are only 2 of those dual op amps. That's 4 output channels. Where are the other ones? Anyone see them?
 

MCH

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@MCH andI too am interested in the output section. Thank you @JSmith for the pictures! I see the OP1678 in first picture, but there are only 2 of those dual op amps. That's 4 output channels. Where are the other ones? Anyone see them?

Hi muehleisen, those 2 op amps are powering the two es9080 DAC chips. They are not in the output stage.

See discussion starting in this post:
Post in thread 'Is there any multichannel DAC easy to DIY in 2023?' https://audiosciencereview.com/foru...el-dac-easy-to-diy-in-2023.46788/post-1718697
 

muehleisen

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Hi muehleisen, those 2 op amps are powering the two es9080 DAC chips. They are not in the output stage.

See discussion starting in this post:
Post in thread 'Is there any multichannel DAC easy to DIY in 2023?' https://audiosciencereview.com/foru...el-dac-easy-to-diy-in-2023.46788/post-1718697
Thanks @MCH that makes sense (Although such low noise/distortion op amps seem overkill for just biasing or powering a DAC).
So maybe the unmarked chips quad op amps?
Or is the DAC directly connected to the outputs?
I'm looking at feeding a FLEX 8 into a icepower amp board that is not a super high impedance load.
I might want to build a buffer amp if there are no output buffers in the flex8.

Thanks,
 

MCH

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Or is the DAC directly connected to the outputs?
i have no idea. What i know is that the 16 channels out of the DACs are summed in pairs, what should be more than enough. But the blurry picture seems to show something else than a resistor and capacitor per channel, so there could be something else going on at the output.
 

Draki

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mata7

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hi guys i hope some one can help me out please, my Minidsp 2x4 HD just stop working after 4 or 5 years, so i need to get a new one, now i have 5 subs and i was considered the Minidsp Flex Eight but I'm confuse because i don't see any analog in, i only need it for subs, so how do i make this work like i do on my 2x4hd, thanks
 

Boppo84

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If you only use 5 channels for the subs, you could connect it digitally and use it as an DAC for your main channels. If you use ARC, than take the Flex HT. If analog in is a must, use the Flex HTx.
 

wgh52

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@mata7

Now, if you really only need to DSP the five Subs, I'd propose to buy a new 2x4 HD.

My question to you would be, though: Why do you need and AD Converter fo the subs? ...maybe because your System set-up is all analog? Maybe there's a "better" alternative solution?

If you want to progress in DAC quality, the Flex Eight is a great alternative, a more powerful platform (i.e. you can use it as DAC for the main channels as well) and it provides higher fidelity than the 2x4 HD. Yes you'll need an ADC, but a decent Quality external AD Converter (i.e. better than 2x4 HD offers anyway...) helps you to invest maybe 200-300$ less than for a Flex HTx.

Greetings,
Winfried
 
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