[atx2014]

can anyone tell me what tube it is? i ordered upgraded GE 5670 tube. but i can't see the GE 5670 green print on the tube. nothing. i can see 5670, that's it.

 

[HOLLOWCOW]

This or the modi 2 multibit to pair with the speedball?

 

[bharris]

I have this same question ^

 

[GotNoRice]

can anyone tell me what tube it is? i ordered upgraded GE 5670 tube. but i can't see the GE 5670 green print on the tube. nothing. i can see 5670, that's it.

I realize that this thread is starting to show it's age now, but I am curious if you ever found out more info about that tube. Looks very similar to the one I got pre-installed with mine

I finally got my D2 a few days ago. Then today my first set of tubes to roll arrived. I was able to find a 3-pack on eBay that had one Sylvania tube and two GE tubes. The two GE tubes are a 2-mica GE JAN 5670W with teal GE logo and lettering, and a 3-mica GE 5-star 5670W with grey logo and lettering.

I got my unit pre-upgraded with the OPA627 OpAmps and the "GE5670W" tube. From what I have read and from what I have seen in the pictures that others have posted, I expected that the pre-installed "GE5670W" tube and the GE JAN 5670W that I got from eBay were going to be very similar if not identical. I was very surprised to find that they have almost nothing in common, don't look anything alike. It doesn't look anything like the 3-mica GE 5-star 5670W that I got either.

The pre-installed tube has no GE logo at all, and the only lettering on the tube at all simply says "5670" in grey (not 5670W).

These are some pictures I took to compare the pre-installed tube (on the right, supposed to be a "GE5670W") to the 2-mica GE JAN 5670W that I bought (on the left). The 3-mica GE 5-star 5670W is currently installed in the D2 which is why it's not in the pics.

The fact that it has no GE logo on it, does not look anything like the other GE tubes that I got, only says 5670 (not 5670W), etc, makes me wonder what tube they actually gave me. Any idea what kind of tube this is that my unit came pre-upgraded with (the one on the right in the pics)? Has anyone else who bought a unit with a pre-upgraded "GE5670W" ended up with an installed tube that looks like the one on the right?

 

[rishabhgkp]

I guess the thread is dead but trying my luck here. Has anyone upgraded from D2 (many must surely have) and found something better in the range? Is Modi Multibit better or something in the sub 600USD bracket?

 

[GotNoRice]

Has anyone upgraded from D2 (many must surely have) and found something better in the range? Is Modi Multibit better or something in the sub 600USD bracket?

The problem is that "better" is an incredibly subjective term. DACs have been around for almost 40 years at this point, and are a very mature technology now. There are no longer really any serious deficiencies that are "fixed" by upgrading to a newer model. That is why so many DACs these days have tubes in them, which actually do nothing other than add distortion, because it's now more about finding a sound that you prefer rather than what is "better". Even if someone switched to another DAC and they thought it was an improvment, that doesn't mean that their new DAC is "better", it just means that it suits their particular tastes. Your tastes and theirs might not be the same.

 

[starck86]

I guess the thread is dead but trying my luck here. Has anyone upgraded from D2 (many must surely have) and found something better in the range? Is Modi Multibit better or something in the sub 600USD bracket?

I was wondering this too. Here’s my experience as someone who uses the D2 mostly for tv, movies, and games in the living room with a hifi setup:

I decided to try a fully upgraded xiangsheng DA-05BII on a limb after reading some translated discussions on it somewhere.
Overall, it is an upgrade for me (though how much one is another story). The DA-05BII also plays nicely with IEMs, as well as speakers (and sounds quite nice, comparable to the N6II at the very least, I think). In contrast, the D2 was always a little too noisy and couldn’t really be used properly with IEMs, at least for me. So the decrease in signal noise is nice as well, though slightly more subtle when comparing using speakers.

As for the sound signature, I personally find the DA-05BII to have a bit more bass than the D2, but it evened out a bit over time, and it seems more or less ‘what it should be,’ and not overwhelming or anything like that. It sounds detailed (but not analytical) and has nice sound staging; again, kind of a similar signature to the D2 maybe, with a little added bass.

The sound signature of the DA-05BII will depend partially on the opamps that you have in there. Speaking of which, it also has 3 spots for swappable op-amps, and a 5670 tube slot just like the D2. That was a bonus for me, as I could easily re-use some of my D2 mods. I also found that upgrading the two polypro caps in the tube circuit seemed to really open up the DA-05BII, though at this point the amount spent on the DAC and upgrades...approaches the level of another DAC purchase in itself, so I question my own sanity, partially, in doing this. That being said, it’s been fun to mod, no regrets. I’m now at the point where I’d love to upgrade from the DA-05BII (though it’ll stay in my system); I just can’t decide where to go next.

TL;DR: There are better options, a number of which I’m looking for as well, but at the very least the DA-05BII deserves an honorable mention as a possible upgrade candidate.

 

[GotNoRice]

I have 2 opamps that I want to try (not three). I'm curious about trying them in my D2.

I know that the D2 uses three and that it's recommended to replace all of them at the same time, but if I were to only replace 2, would that harm anything? The 3rd would either be a OPA627 or LM4562. Assuming it's safe, which two would make the most sense to replace?

 

[]eep]

that this is still active. I wouldn't waste any time on this obsolete dac. I can't even remember what dac chip is inside, but if it needs an active output it must be delta sigma. An old design. Newer ones can be ok, within reasonable cost. But a bunch of opamps and tubes cost as much as a proper new dac. Which will sound better.
I never considered tubes following opamps a good idea for a dac. It's always the worst of both worlds. Not the best. I'm a fan of tubes, I even have a big stash of 5670 tubes (about 120) but this design uses the tubes as an afterthought, a flavour, a gimmick. The opamps do the work, the tubes are the ketchup on the steak. I think bypassing the tubes will even clear up the sound.
Digging in memory I remember having one of those here, the Chinese branded same model. A friend asked if I could modify it. Back then i didn't get much further than a few GE5670 tubes. Too much low quality electronics in the output stage (output caps). The sound was pleasing but not well defined, lack of detail and space. Not that great imo.

To answer the question: opamps are stereo, so if there are 3 the
left signal will go to opamp 1 L, then to opamp 2 L, then 2 R. That is 3 stages. So if you have 2 better opamps you can replace the 2 latter, they will be symmetrically placed on the board. It's not hard and there's no risk if the opamps are compatible (and same Voltage or a bit higher).

To answer the previous question: what would you upgrade to at ~$600? Not that i was ever tempted to buy the Maveric, but that would be a NOS, filterless R2R dac with a passive output stage. My old dac was a Teradak at similar price (great dac) and at 700 i just bought the Denafrips Ares II. At that pricebracket that is pretty much a no-brainer. That is a totally different quality level.

 

[starck86]

that this is still active. I wouldn't waste any time on this obsolete dac. I can't even remember what dac chip is inside, but if it needs an active output it must be delta sigma. An old design. Newer ones can be ok, within reasonable cost. But a bunch of opamps and tubes cost as much as a proper new dac. Which will sound better.
I never considered tubes following opamps a good idea for a dac. It's always the worst of both worlds. Not the best. I'm a fan of tubes, I even have a big stash of 5670 tubes (about 120) but this design uses the tubes as an afterthought, a flavour, a gimmick. The opamps do the work, the tubes are the ketchup on the steak. I think bypassing the tubes will even clear up the sound.
Digging in memory I remember having one of those here, the Chinese branded same model. A friend asked if I could modify it. Back then i didn't get much further than a few GE5670 tubes. Too much low quality electronics in the output stage (output caps). The sound was pleasing but not well defined, lack of detail and space. Not that great imo.

To answer the question: opamps are stereo, so if there are 3 the
left signal will go to opamp 1 L, then to opamp 2 L, then 2 R. That is 3 stages. So if you have 2 better opamps you can replace the 2 latter, they will be symmetrically placed on the board. It's not hard and there's no risk if the opamps are compatible (and same Voltage or a bit higher).

To answer the previous question: what would you upgrade to at ~$600? Not that i was ever tempted to buy the Maveric, but that would be a NOS, filterless R2R dac with a passive output stage. My old dac was a Teradak at similar price (great dac) and at 700 i just bought the Denafrips Ares II. At that pricebracket that is pretty much a no-brainer. That is a totally different quality level.

Hey, to each their own.

I’ve had the D2 w/ opamp/tube/output cap upgrades since it maybe first released, and more recently I upgraded to the XiangSheng DA-05BII (also with all the options and upgrades coupling caps). The maverick is a fun entry level DAC. The DA-05BII is like a next step up. Each upgrade made considerable difference and was pretty fun. Both use the same opamps, tubes, and coupling cap size. I still use the D2 in my second stereo system. I love the sound of the DA-05BII right now... Would like to try the denafrips Aries and compare the two...

Edit: what was op’s question again?

 

[]eep]

really no offense. If you don't like to read about my experience or don't like to be advised than just don't read.

I've restarted my audio hobby when my expensive Audio Note amp broke and i started looking for answers. Searching the web I found out about Chinese tube amps and was astonished by their price. This was over 15 years ago. I bought a true single ended amp that cost me less than the repair of the power tranny in my Audio Note. Because its wasn't sounding good (no sub 100 Hz bass) I started modifying. Then I bought a tubed cd-player and started modifying its dac and PS. I modified the hell out of it and it just blew my old high-end cd player out of the water. I payed less for the new Chinese one than I got for the old one (cd-players don't sell well). Mind you, it already sounded better stock, with the cheap gettoblaster dac-chip, cascade of electronics in the I/V stage and cheap caps before and after the tubes.

I took out the rubbish up and down resistors/opamps out so the chip fed the tubes directly. Second I improved the caps and tubes. Third I improved the power caps. Then came the resistors around the tubes to avoid overmodulation of the tubes. And finally i replaced the cheap dac-chip with a different daughter board with a proper top of the line AK chip (cut the opamps and went straight to the tubes). Since that daughter board had coax and opt inputs I can still use it via the optical input as an external dac. I still use it for comparisons. That cd player cost me €250, the daughter board €50 and tubes and caps 10-20 a piece. So thats not exactly entry level (I know what sound good) but the price is comparable. And I have played around with almost all parts save the transport.

Later I bought a cheap 4xTDA1543 NOS R2R dac for €45 just out of curiosity. That sounded different. A bit held back, but really good. Then I looked inside and found the main culprit: elco output caps (due to space constraint). So I pulled the same tricks and modified the output stage to a minimalistic passive output stage. I also made a star ground, reduced working voltage and added a power switch. Extra cost €1 plus an hours work. The sound is comparable to the Denafrips. Truely high end and gives most really costly dacs a run for their money (or really: a trashing). Point is; there is no need for tubes or opamps since the output signal of the dac-chips is high voltage/low current.

I also have a modern ES9038Q2M dac that cost me €150, just as is it sounds awesome. I could live with it. It has more features that make it really versatile (proper usb, DSD decoding, Apt-X usb). It sounds different than the 4xTDA1543, wider soundstage and enhanced but artificial highs. But no tubes needed or wanted.

All in all, I have heard plenty tubed dacs but none of them are really neutral and clean sounding. R2R doesnt need tubes, only delta sigma. And I found delta sigma artificial sounding and all d/s dacs are made of the same building blocks. So no tubes for me in the digital source path. Not even when its properly implemented (unlike in the 'TubeMagic').

 

[starck86]

No offense taken. I enjoy reading about other people’s experiences, and sometimes it helps me to decide where to move from my current stuff!

I have tried and A/B’d a bunch of DACs as well...doing so with a R2R DAC is next on my list.

I don’t think I could say one type of DAC (sigma vs r2r vs etc) is better than another...It all just depends on the implementation

The D2 is a budget DAC that’s pretty old now. I only ever used it in my home stereo. Actually had 2 of them and gave one to my brother since he has never had a DAC for his home stereo. Now I use a XiangSheng DA-05BII at the moment.

In my experience, tube buffers need a good NOS tube and typically better coupling caps than are provided in the unit. (Sounds like you already found that out based on your mods!) I’ve found that Mundorf evo silver/gold oil’s provide a huge improvement as coupling caps. Russian PIOs are also nice. All depends on the equipment they’re going in. Stock Russian/Chinese tubes sound like garbage and usually go in a pile.

There are lots of tubes out there (and I have quite a lot here that I have tested, and maybe 10+ in the 5670/2C51/6385 family). The best, most even/neutral and quietest/cleanest tube I have tried is the bendix 6385. I suspect some may find it too neutral. There are a few others that come pretty close, and still others that sound very nice while adding a bit more flavor to the sound.

In my experience, some tubes just do not sound very clean to begin with, and they are usually either near EOL (this is why having a tester is handy), or they’re just a bad tube from a lot so they sound a bit off compared to how they should sound (this is why purchasing on auction sites from unknown sellers can be risky). I have experienced both the former and the latter.

Delta-sigma doesn’t “need” tubes; it’s just a design implemented in some of these DACs.

A proper combo of speakers/headphones, amp, and tube buffer can be very dynamic, sonically holographic, and beautiful. I don’t think any one DAC type is necessarily better than the other; we can probably pick high end DACs with several different implementations that all have different characteristics and are highly regarded.

My point was to help OP and mention that I upgraded from the D2 to the XiangSheng DA-05BII, it uses 3 of the same opamps, same tube, same coupling cap value, and might be worth a consideration as an upgrade for OP in the future if they do decide to buy the opamps now.

My experience
The DA-05BII is darn clean sounding. I listen to it mostly on my living room setup (restored tube monoblocks from the 50’s with an ultra linear design, along with a Sansui 999 solid state amp), and less so with my headphones. It sounds very nice with headphones though; arguably besting (or equivalent) to my N6ii when feeding a Quicksilver headphone amp, perhaps. It’s pretty close. The maverick D2 was somewhat noisy in comparison with headphones for sure. (Again. It’s old. Lower priced. Not a fair comparison.)

I’m just not sure how your comments fit in here. Do you/did you own a D2? I’m a bit confused on this part. And, if you have not tried Sparkos op-amps, I don’t know whether it is fair for you to compare these things and just dismiss them.

Yes the DAC is old and there are better out there now. But that’s not what OP was asking; they wanted to know about op-amps. We’ve hijacked their question and to be honest I feel quite badly about that.


I will see if I can find a place that will let me audition a r2r; not sure where I can do that for a Denafrips DAC though.

 

[]eep]

I never owned a D2 but I had one in my system to evaluate and see if I could upgrade it.

I don't think I hijacked the question, I just want to warn that the question is not very relevant since the unit is really not worth the upgrade. But I answered it anyway.

To clarify once again: delta sigma dacs are low V high I output so they always need amplification to reach >250mV (better said; an active I/V stage). Cheaper dac-chips have opamps built in but low quality. So you need either transistors, opamps or tubes. So as a design purist I say; pick one you like best and optimize that. Since 2 steps up often suffice 1 stereo opamp or tube per side will do. So don't go namedropping and make it an amplification roller-coaster up and down (we use tubez X, hiQ opamps Y, resistors Z). Useless and counterproductive. I heard it so many times from Chinese products and it does not work.

R2R are different. There is no need for an elaborate I/V stage. No tubes or opamps mucking up the sound, no hiss , no crackling, no added distortion, euphonic harmonic or otherwise. And the R2R NOS also avoids HF artifical 'detail'. It is not just a matter of frequency control or flatness but the superiority of R2R lies in it's correct temporal behavior. There is no unnatural pre-echo or pre-ringing. That's like you see ripples appear in the water before the stone hits the surface. Every delta sigma does that, all effort on newer technologies is put on reducing that effect inherent in using 1bit vs multibit. It's not a matter of preference of which distortion you like best and definitely not of frequency curve. Mind you: tubes can't help you one bit in getting rid of that pre-echo.
MQA is claiming to be such a technology but I decided not to care about it after trying some recoded files. I rather go for native DSD and at least 96kHz PCM. I think it is merely one more proprietary distribution marketing and copyright scheme.

The quality of dacs has everything to do with timing issues. As well in the signal handling (input, still digital), conversion system (DS, FPGA/R2R chip or discrete) and I/V stage. A little bit in output impedance. In my experience with R2R you are betting on a thoroughbred. With D/S on a blue collar workhorse that might perform better than expected (sometimes with the help of pharmaceutics) and an old DS chip with opamps and tubes is definitely betting on the wrong horse. Often overpriced and not worth the hassle.

If you really want to save money there are some really good DS dacs out there like es9038q2m chip or ak4497 (...9).They all use opamps which work fine. The ESS is very detailed, the AK is mellower. And some good R2R like Teradak, AudioGd etc. You can have a really good dac at €150-300 already.

If anyone is interested in Denafrips, there is 1 official distributor who is also the cheapest option: Vinshine Audio in Singapore. Also a very nice guy with great support. If you have the money and are looking for a absolutely great dac the Ares II is a no brainer at around $700.

Off topic: feeling badly means your ability to feel is impaired. That's probably not the case here. And there's no need to feel bad either.

 

[starck86]

This is super helpful - thank you!
(It’s all good, btw )

 

[GotNoRice]

I've had the Maverick Audio TubeMagic D2 DAC for a while and I've been going back and forth between using LM4562 Opamps and the OPA627 Opamps that came pre-upgraded with this unit (each two single OPA627 OpAmps on an adapter board to create a dual opamp). Each had it's pros and cons but neither really seemed to be giving me everything I wanted. The OPA627 seemed more smooth, but almost too smooth, to the point of lacking texture in some cases. The LM4562 had more of the texture that I preferred, but can also be just a bit harsh, especially for long listening sessions. The tube output, using a Sylvania 5670W tube, did help, but only so much.

I've had good results with Burson Audio OpAmps in other devices, so I decided to try some Burson Audio V6 OpAmps in the D2. Since the TubeMagic D2 DAC uses 3 OpAmps, I decided to mix it up a bit, with one V6 Vivid Dual and two V6 Classic Dual Opamps, each type in a different stage of course.

Installing them was somewhat tricky, due to the fact that they are so tall, while also being fairly wide at the bottom. Each Burson Opamp comes with an optional riser that can help keep the OpAmp above the surrounding components, but that also makes the already tall OpAmps even taller.

Here you can see all the OpAmps installed using risers. The single V6 Vivid is just short enough to allow the top cover to be installed. Unfortunately, due to the design of the sockets, the V6 Classics in the middle sit just a tiny bit higher, and that tiny extra bit of height was enough to prevent the cover from closing properly. My only other good choice was to try and install the V6 Classics without the risers. That made them awfully cozy with some of the surrounding components, but seems to not be a problem. That made them shorter and the cover is able to close correctly with them installed.

Listening tests were done using my Little-Dot I+ Headphone Amplifier, using Sylvania 408A tubes, powering a set of Beyerdynamic DT770-Pro 80-Ohm headphones.

During my tests, the difference sounded fairly subtle. They definitely have texture, more like the LM4562 than the OPA627, but they also were not fatiguing at all. Vocals were vibrant and and the mid-bass was very energetic. When I really noticed the difference though, was when I took them out. The OPA627 and LM4562 OpAmps just seemed dull compared to before. Not terrible, but there was clearly something missing.

Both the Tube output and the Normal output seemed to benefit from the upgrade, but I still prefer the Tube output overall, as was the case with the previous OpAmps that I used.

Hopefully there will be no long-term issues with the V6 Classic Opamps being in contact with some of the surrounding components, but so far there are no issues. It turned out to be a very worthwhile upgrade.