[prfallon69]

Could somebody please let me know if it’s possible to use the Topping D50 as the Dac with the Matrix M-Stage HPA3u.

-Paul-

 

[raoultrifan]

Yes, seems that it has RCA inputs: http://www.matrix-digi.com/uploads/product/HPA-3U/03.png.
Same conclusion after reading http://www.matrix-digi.com/pdf/HPA-3U_plus_Manual_EN.pdf, page 4.

 

[prfallon69]

Yes, seems that it has RCA inputs: http://www.matrix-digi.com/uploads/product/HPA-3U/03.png.
Same conclusion after reading http://www.matrix-digi.com/pdf/HPA-3U_plus_Manual_EN.pdf, page 4.

Thank you.

-Paul-

 

[omegaorgun]

I have the 2C, changed the opamp to an OP275 it's a decent amp with more low end kick and power than my NFB.11. I was confused by the output of 110 mw @32ohms thinking it might be crap but it's a powerhouse with a very tight focused sound.

 

[mikaelmark]

QUOTE="raoultrifan, post: 12458973, member: 386058"]
I'm not sure how will you A/B test headphones with Schiit Sys, because this only has RCA plugs. Perhaps this would be a very good A/B testing tool for single-ended DACs only, but not for single-ended headphone amplifiers.

Here's what I'm using for A/B testing, either single-ended DACs, either single-ended headphone amplifiers (6.3mm jack directly plugged into 6.3mm amplifier's output connector):

​

It's completely DIY and quite easy to build and with good components quality. One PCB divided into 2 sides: the left half used for headamp testing and the right half for DAC testing.

On the left side of PCB there are 2 x 6.3mm jacks used as source inputs that might be connected to 2 different headphone amplifiers and the blue 6.3mm connector can be connected to a good and detailed pair of headphones. The silver/red switch can be used for rapid switching between the 2 sources.

On the right side there are 2 sets of RCA inputs that might be connected to 2 DACs and the 3'rd set of RCA plugs is used as output to a transparent headphone amplifier connected to a good detailed pair of headphones. The silver/red switch can be used for rapid switching between the 2 sources.[/QUOTE]

Hi, Raoultrifan!

Nice to read your meticulous and detailed review about the Burson Play, ealier this year!

As I now has been choosen for testing of the headphone amp Fun from Burson, it would be helpful to build something similar to your A/B-tester. I´m thinking about one with two 6,35 mm (1/4 inch) TRS male jacks that can be connected to two headphone amps out. Both are soldered to cables that comes together to a 6,35 mm TRS female socket. Between, there will be a switch to chose what amp to use at the moment.

Do you think it will be enough to switch source only with the Ground, so the Left and Right channel from both amps will always be connected to the headphones? Is that the way you have done?

 

[raoultrifan]

Hello,

No, sorry...current might flow between one device into another and we don't want that to happen. Why not using something cheap and cheerful similar with one from below?
- https://www.amazon.co.uk/3-5mm-Audio-Music-B-Switch/dp/B07622SYCF
- https://www.amazon.co.uk/dp/B07836JJ2Z/
- https://www.amazon.co.uk/Way-Cd-Aux-Stereo-Switch-Black/dp/B000KVODHA/

There're also with 3.5/6.3mm jack plugs as well, just nee to dive deep a bit more on Amazon or electronics related web shops.

 

[mikaelmark]

Thank´s for your reply! Two of those link´s are for RCA input and the other is 3,5 mm (not in stock).

I found one at eBay, and the Product description state it´s correct: "Want to switch between 2 different 1/4" TRS audio input sources into one pair of headphones". -But hey; $100 + shipping!!
https://www.ebay.com/itm/1-4-TRS-St...977092?hash=item212adbedc4:g:U30AAOSwy79Zcot8

I think a DIY with three switches will do the job fine.

 

[raoultrifan]

I'm sure you'll find a cheap one to purchase, but you can DIY one, of course.

 

[mikaelmark]

Yes, I´m definitely gonna DIM it (DoItMyself), as I have dozens of 6,35 mm jacks, sockets and several meters of Van Damme Tour Grade Classic XKE starquad mic Cable.

For the switches, don´t even Think I must use three, only two should be fine as only the Ground always/pemanent connected between the amps should not do any harm or have any current floating, don´t you think also?

I hope my Fun will arrive soon! Gonna start a new thread for this review, I think.

PS; I told Charles you helped me with this, thank´s a lot raoultrifan!

 

[raoultrifan]

Looking further for your review and, of course, for the A/B-testing device.

 

[mikaelmark]

Finished it some days ago, and keep in mind I did it with a broken wrist for left hand!

Soldered it directly to the female socket without any PCB.

There are five buttons, so pushing the left one in, it will activate amp 1, a slight push at any other button will release the left one and activate amp 2. And if in future, I want to use any of the other buttons, I can solder for example an A/B-testor for DACs with RCA.

 

[Filipash]

https://imgur.com/a/nqMmkWr

Hi everyone!
Here I haveme some pictures of the running temperature of hpa-3b amplifier and temperature of op amps
Sparkos vs stocK
i cant upload pictures, may be i am doing something wrong...
stock op amp case temperature 38.6c, op amp temperature 65.4c
sparkos op amp case temperature 49.3c , op amp temperature 100.5c

 

[raoultrifan]

Hi there,

Can't find any pics, sorry, please re-attach.

However, per your temps, please remove the Sparkos because they're most likely oscillating. Feel free to replace them with the original LME49860 or with something else able to opearate to 36V (e.g.: OPA1652 or similar).

 

[Filipash]

Hi there,

Can't find any pics, sorry, please re-attach.

However, per your temps, please remove the Sparkos because they're most likely oscillating. Feel free to replace them with the original LME49860 or with something else able to opearate to 36V (e.g.: OPA1652 or similar).

Thanks for reply , already removed them
Had one more problem with sparkos at high gain , above 60% of volume Matrix turns off , turns back on on low volume

 

[Filipash]

Hi there,

Can't find any pics, sorry, please re-attach.

However, per your temps, please remove the Sparkos because they're most likely oscillating. Feel free to replace them with the original LME49860 or with something else able to opearate to 36V (e.g.: OPA1652 or similar).

https://m.imgur.com/a/nqMmkWr