Donald North Audio — Owners Thread

Thank you for confirmation and apologies for any confusion I may caused. Maybe I misunderstood.

 

Very off topic

I asked Thomas if the gain and plate resistance of the TM300B is the same as the stock 46. I don't really believe a 300B can be voiced unless it actually has the higher resistance and I'm sure the dual grid of the 46 plays a vital role of its sound, that and the copper grid.

Elrog is very guilty of having tubes with NOS numbers which don't share the parameters. From personal experience, the Elrog 300B has a gain of 3.3 where all other 300B have 3.9 and current bias is lower overall, the Elrog 274B has much higher voltage drop than a typical 274B and the 801A biases quite differently than any other 801A. This is pushing the limits and taking advantage of unknowing customers with the saving grace being Elrog sounds so good I forgive them for the white lies. I'd expect the TM300B to have the same 5.6 gain as the 46 and similar plate resistance at the same operating point of -33V, 250V and 2450Ω otherwise it's just smoke and mirrors.

 

Where in the US can you buy Elrog Tubes?

 

You can get them from either Parts Connexion or vkmusic.ca, the latter providing better prices but all ordering has to be done via email/phone.

 

Wonder what the price diff is to ordering direclty

 

Direct is 600 EUR incl. shipping for the 5U4G

 

@m17xr2b - Not sure if you have ever tried it in your Stellaris, but if so, how does the Elrog 274B compare to the WE274B in the Stellaris? If it matters, I'm going to be running with various 2A3 and input tubes you sent me... After 1+ year of searching, I still can't find a reasonably priced WE274B for a reasonable price (<$400-500USD) with enough life left, etc. ... I don't see the new WE 274B coming out for at least a few years if at all.

On a different note - first time listening to Stellaris in about a month or too with pleb 5U4G tubes but my initial review and impressions still stand - Stellaris too stronk.

 

To put this a different way, capacitors are like water storage tanks, the rectifier is the pump, the larger the tank the greater work required for the pump to fill it in a certain time, 5U4G is a workhorse and can deal with a large tank, 274B is a tiny pump and can only handle 5 to 10 times less than what a 5U4G can. It will burn out eventually if you're asking a small pump to fill a huge tank in the same amount of time the big one would.

 

Is it worth investing in the input tube at all and is there a consensus on good input tubes that are easily available? Not even sure which ones I'm using right now, probably triple mica or some other 6N1P.

 

I use my WE 274B very sparingly . It sounds too good not to use it once in a while. It was a used tube when I got it but strong.
I do the same with my WE 422A. The vast majority of my listening is done with my Acme Supremes, RT Select and EML 5U4G

 

422A can be used to your heart's content, I somewhat doubt a strong one can be worn out in a lifetime in the Stratus or Stellaris. It's an even beefier rectifier than 5U4G and can take a ponding.

 

Got the Elrog 5U4G:
- Very bright (visually). Not sure I'd recommend it if your amp was sitting in clear line of sight.
- Tall-ish. I had to reconfigure my rack to fit it. It barely fit the ACME 2A3 before but not the Elrog

 

Any impression or too early to tell? I have a bit of an interest in that one but havent come across much online.

 

Which rectifiers do you like?

regards, BZ

 

First of all, thanks to Donald for the beautiful amplifier. Just received my DNA Stratus two days ago here are some pictures. The strange thing is the rectifier tube is the hottest out of them all. This is measure with my infrared imager after about 2 hours running with room temperature around 72F or 22C.

Will update the sound impression in about two weeks given the fact I also install the Unison usb upgrade on my Yggdrasil on the same day.

 

Just my impression on the DNA Stratus and my setup:
Foobar ---> Schiit Yggdrasil A2 Unison usb --> DNA Stratus/Bottlehead Crack Speedball --> Sennheiser HD650/800

When I first received the Stratus I thought it would be steroid amp with that much power it should boost everything. Upon further listening in a few words describing this amp are huge soundstage, instrument separation, effortless smooth, details/layering and refining.

First thing strikes me is the huge soundstage the HD650 on the Stratus sounds larger than the HD800 on the Crack Speedball amp. Which also making the presentation less intimate or warm and due to the expand soundstage acoustic music sounds amazing especially string instruments, I don't really listen to classical or orchestral music but for those who do this amp will do wonders. Not sure if I am using the correct term, but the transient response is fast when the sound of the instrument begin to end then shift to next instrument I don't heard any delay in that term.
Stratus extract microdetails from my album that I haven't heard before like hitting the cymbal and the loudness gets progressively louder as oppose the to same loudness on the Crack speedball.

Stratus is very smooth especially with the HD800 is to the point sounds smoother than the HD650 making it better for long hours listening, not to mention HD800 have no clamp force as oppose to my HD650 which I own for 10 years still clamp my ears hard. Vocal on the neutral side, the Crack speedball definitely warmer perhaps due to the smaller soundstage making it having a more forward presentation. As for bass I am not the right person for this, because I am not a basshead I can hear the bass is extend well and the impact is good to relative. However, one thing I could say about the bass is fast. Instrument separation is fabulous due to the large soundstage everything is spread out don't sound congested or mixed up.

Closing thoughts, I think HD650 is a double-edge sword with the Stratus at least in my opinion, Stratus make it sounds like a HD800 better instrument separation, layering, and etc.. However, the HD650 lost to me what is the most important feature is the lustful vocal like I said earlier the soundstage push the presentation back if someone want a HD650 with HD800 technicalities I think that is what the DNA Stratus + HD650 sounds like. HD800 is a perfect pair for the DNA Stratus I think I read somewhere that Donald did tune this amp with the HD800.

Another thought, I don't think the Schiit Yggdrasil actually pair that well with the Stratus because this review I never mention Clarity, seems to me there is a layer of haze over the music I read in another thread when someone compares the Yggdrasil LIM to the A2 Unison have similar experience. So, I already setup an audition to the Rockna Wavedream Edition SE next week see if my impression will change.

 

In my experience, AES3 from Pi2AES gives a noticeable improvement in clarity/haze reduction over Unison USB from a good source (Allo USBridge with linear power supply) with the Yggdrasil A2.

 

It might be your cables or setup. I also have Stratus and Yiggy, Ny setup is Source to Yiggy then SE to Stratus. All my wires are Wywires Diamond. My tube set is Ruby Tiger select input tube, rectifier is EML and power tubes are Acme select by Grant Fidelity.

 

Honestly, I am not too familiar with the Allo USBridge. I read about the PiAES is similar to a network streamer if I recall, but now the Allo isn't it the same thing as the PiAES or that is just acts like a usb filter?

 

I try the cable upgrade as last resources, from my experiences there are more placebo effects. As for tube rolling, I might have to do it when fund permits. Thanks for your suggestion though.