Topping DX7 - DAC and balanced headphone amplifier
Aug 2, 2018 at 2:41 PM Post #286 of 468
I’ve been loving the DX7 since I purchased it, but there is a huge glaring issue that no one seems to have reported on this model. I primarily bought this unit to use with the optical out on my TV for gaming. It does a stellar job, however I frequently have audio drops where “48Khz” flashes on the unit’s display, which last for about 1-2 seconds before the signal returns to normal.

I reached out to Topping’s customer support on this matter, and this was their reply:

Thank you for contacting TOPPING support. We are happy to assist.

According to our analysis, your DX7 has no problem. We designed DX7 to slowly increase volume of output when sudden input a signal. This will aviod the sudden sounds which make users discomfort. Output of your TV probably will break off and recovered in a short time, but DX7 captured this break off and slowly increase volume at signal's recoverly. So you see this situation, some users who use apple's optical output met similar problem.

They told me that it’s not something I can fix on my end, and would require special tools for a firmware update that only they have access to. I’m super bummed about this, as I literally love everything else about the unit, but the frequent audio drops have made it unusable for me. I have a Schiit Modi 2/Magni 2 combo, Yamaha AVR, a cheap Vizio sound bar... none of these exhibit issues when using optical input, it’s only the DX7.

I know this isn’t a common use case for most people here, but I figured I’d post this as a warning to those planning to use their optical output from their TV on this. I primarily chose the DX7 because it’s one of the few combos with a good remote control, making it ideal for couch usage.

With that said, I do find it strange that no one on the internet has reported this online. Is there anything I can possibly do to fix this issue on my end?

I am having what appears to be the same issue with my DX7, using an iPhone as the source plugged into the USB input.
Randomly the sound will cut out for a second, then start up again.
If I am interpreting Toppings response correctly, I should be able to rewind the song and it would cut out again at the same point to protect me from sudden sounds that would give me discomfort. But that does not happen, it does not cut out at the same point it did last time. The cut outs are very random.

I will email Topping to see what they say, but I’m curious if there has been any progress with this?

Thanks
 
Aug 3, 2018 at 7:34 PM Post #287 of 468
I currently have a Jotunheim DAC, connected through XLRs to a pair of Adam A3Xs and through the unbalanced headphone output to some Sennheiser HD650s.
I rarely use my headphones for music, don't listen to high-resolution audio, and to be honest there's nothing that I can find that's 'wrong' with the Jot; it just runs super hot.

Similarly, I probably don't NEED balanced preamp out... but I live under large antennas in Seattle and going balanced has helped with noise in the past, even with super short cables. Whether it was something else (I also improved my power supply on at least one setup) or the balancing, I don't know, but I stopped messing with it since.

Now the DX7s has XLR outputs... but specs don't mention them being balanced. That makes me think they are NOT. Is that correct?

If I am wrong and they are, would the DX7 be a worthy change vs. the Jotunheim, for those who listened to both? (I'm not expecting a drastic change one way or the other: I just want to avoid disappointment. Hell if it sounds exactly the same and runs cooler, that's already a bonus!)

Thanks!
 
Aug 4, 2018 at 8:44 PM Post #288 of 468
How's the amp's power for planar magnetic headphones, I looking for a good dac/amp @ this price point for my shop..Thanks
 
Aug 4, 2018 at 8:46 PM Post #289 of 468
How's the amp's power for planar magnetic headphones, I looking for a good dac/amp @ this price point for my shop..Thanks

I use the DX7, balanced, to my HE560, Audeze Sine, and UM ME.1 planar IEMs with no issues. I'm hovering -25 to -35dB on them usually, -30dB being optimal for most songs -- so plenty of head room.
 
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Aug 28, 2018 at 12:56 AM Post #292 of 468
Mine power cycles when using Eitr so.. best of luck.

Also,
There was a major quality issue with my DX7S. When I started modding it I noticed the heatsinks were not level and when correcting it I discovered there is no thermal pad either! The heatsink was only making side contact on one chip so I'm thankful this was caught early. So if you are comfortable talking the DX7S apart I'd recommend this fix. It's easy, just pull front first by loosening the side screws and unplug. Then unscrew the bottoms and slide board out from the back. Unscrew sinks from back of the board and apply a thermal pad or paste.
IMG_20180827_213101.jpg
 
Sep 1, 2018 at 9:59 PM Post #293 of 468
I should probably post this in the FS/FT thread, but would anybody be interested in trading their silver DX7s for my like new black DX7s? My amp and color scheme choices are white/silver, so I'd like a DAC to match.
 
Sep 14, 2018 at 7:58 PM Post #294 of 468
I received my Topping DX7 in black a few weeks ago. The sound quality...and great build quality...was a very pleasant surprise. I have a dedicated DAC for my audio-only needs already, so I bought this DX7 primarily for lower-resolution sources like the Toslink outputs of my TV, my Wi-Fi-Radio and my ASUS motherboard Toslink output. This combo DAC/headphone amp sounds excellent! It drives my Anandas, HD800s, and Grado 325e without any difficulty. Very neutral sounding. Great soundstage, pretty balanced frequency response (no major peaks or valleys I could detect with program material I'm familiar with). I use it only in balanced mode as I had a cable made for the Anandas, since they only come with single-ended cables. Balanced sounds more lifelike to me than single-ended...greater immediacy...probably because the amp's slew rate is doubled in balanced configuration and you can get it louder as well. I owned the Aune S6 unit two-months ago for just 2 days...and had to return it due to a cold solder joint in one of the balanced connectors. The guts of the DX7 and the build quality of the Topping are first rate. It can get quite loud with either the Ananda low impedance cans, or the HD800s high-impedance cans. It is just one more component out of China that has convinced me that if you want excellent sound, you really can get it from an Asian manufacturer. Many years ago, that may not have been as true, unless we were thinking Nakamichi or other Japanese products (Technics elite, Sony, etc.). I really enjoy the dynamics, sound-staging, and resolution of this piece. It handles complex orchestral passages with ease, and has a great low end. I have the single ended outputs driving my Adcom GFA 555II and frankly, the low end kicks ass into my old Dahlquist DQ10s and a pair of Sequerra bookshelf speakers. This one is a keeper.
 
Oct 26, 2018 at 9:09 AM Post #295 of 468
There was a major quality issue with my DX7S. When I started modding it I noticed the heatsinks were not level and when correcting it I discovered there is no thermal pad either! The heatsink was only making side contact on one chip so I'm thankful this was caught early. So if you are comfortable talking the DX7S apart I'd recommend this fix. It's easy, just pull front first by loosening the side screws and unplug. Then unscrew the bottoms and slide board out from the back. Unscrew sinks from back of the board and apply a thermal pad or paste.

I'd seen your comments about this DX7s problem in audiosciencereview. Apparently there were a few early DX7s deaths that might related to this QC issue you found in yours.

Things got better after you repositioned the heatsinks? What were they used on?
 
Oct 26, 2018 at 10:04 AM Post #296 of 468
The sinks were used on the amplifier chips and mosfets. They had no thermal interface material and were mounted crooked making no contact with one of the chips and only one corner/side of another. I used thermal pads cut to size and remounted the sinks. I never had a failure, but I opened my unit before using it. I just got another DX7s and will post up pictures of it tonight when I crack it open (and if I remember)
 
Oct 27, 2018 at 2:23 AM Post #297 of 468
Same deal, poor contact and no thermal interface material. Not sure if this is the cause of those failures though, it can't hurt. I've been using mine solely as a DAC for the most part and this looks more on the amp side.

IMG_20181026_215508.jpg IMG_20181026_214837.jpg
 
Oct 28, 2018 at 10:39 AM Post #299 of 468
That I installed before putting the sinks back on, yes. The side shot shows how it looked before I removed the sinks.
 
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