Kassandra II Ref E280F options

[mitch2+]

Are they the same pinout?

I believe they are the same pinout. They are both pentodes according to the Siemens' information linked in my earlier post and here.
According to TubeDepot's site (link):

"Having a nine pin miniature base"

Also, according to AI:

"Siemens D3a and E280F tubes are not exactly the same, though they share some similarities and are sometimes used interchangeably. The E280F is often considered a slightly more refined and potentially more "technical" tube, while the D3a might be perceived as having a more dynamic and perhaps slightly darker sound."

I am curious whether anyone has tried them as a substitute for the E280F and if so, whether they have heard differences between the E280F and D3a, and whether the differences are similar to those described above by AI, or whether they hear something else. Maybe another question is, in the absence of E280F tubes, what is the next best sounding tube for these AC DACs? Based on these threads, it seems the E810F may be the next best option and may provide a "fuller sound and more bottom." However, it seems some like the Siemens E180F and even the 6j11p Russian tubes could be a viable option.

 

[Argonaut]

Are they the same pinout?

Yes entirely interchangeable Brad .

 

[Aries Cerat]

Are they the same pinout?

What he means is bias range.
Yes same pinout

E810F,
E180F
E280F
D3A
6j11pe

Drop in replacements for Kass (the last type is a killer tube for TriodeFets )

Best
Stavros

 

[mitch2+]

For my clarity, the lower the bias setting on AC DACs, the potentially warmer the sound and, since the bias setting is shown as a negative number, a greater numeral shown correlates with a potentially warmer sound, correct? IOW, a setting of -260 should result in a warmer sound than a setting of -220, correct?

 

[elrod]

In my system with the Helene, the more negative (-260) you go, all the adjectives improve (clarity, separation, imaging and sound stage). Less negative (-220) all the adjectives seem to lesson and I suppose the sounds goes a bit warmer. Warmer isn't what is predominate compared to the adjectives. I'm running with E280F and the GE/Matsushita GZ34 rectifier

 

[nonesup]

That's how it is.

 

[mitch2+]

Ok, thanks. I guess I had it backwards. I am having trouble achieving the level of warmth/body I was hoping for. Detail is fine but it sounds a bit thin, sort of a similar situation described last year in posts by member skids929. I will try pushing the bias the other way, less negative.

 

[J007B]

In my Helene I’ve found that a bias of -235 is perfect for me.

 

[mitch2+]

Thanks. I am using NOS E280F tubes by Siemens so the bias range is 200-280. I will try 220 and if that goes too far then I can push it back a little. As the rectifier tube, I am using a NOS Mullard 5AR4/GZ34 with an October 1966 date code (B6J5).

Update: This evening, I set the bias at 220 and am now hearing closer to what I hoped to hear from the Helene in the first place. Thank you all for the guidance. Tomorrow, I will put in the Cardas Golden Cross ICs from DAC to pre and hope that gets me across the finish line to where I want to be.

 

[J007B]

I’m using a NOS Mullard 5AR4 1965 date code.

 

[nonesup]

I don't know if a Kassandra data is valid for Helene, my polarization is -250

 

[Mr. Analog]

Dear AC-members,

E810F
E180F
E280F
D3A
6j11pe

I have tried them all in my Helene and I like the E280F and the 6j11pe. The 6j11pe is very similair to the E280f. The 6j11pe is often compared to the E180F tube, but the sound reminds me more of the E280F. The E180F and the D3A are good, but not as good as the other ones. E810F change the sound, it does not sound so refined. But it all depends on the right Bias, your System and your taste.

Regards

Tom

 

[DasguteOhr]

Dear AC-members,

E810F
E180F
E280F
D3A
6j11pe

I have tried them all in my Helene and I like the E280F and the 6j11pe. The 6j11pe is very similair to the E280f. The 6j11pe is often compared to the E180F tube, but the sound reminds me more of the E280F. The E180F and the D3A are good, but not as good as the other ones. E810F change the sound, it does not sound so refined. But it all depends on the right Bias, your System and your taste.

Regards

Tom

The E810F needs more idle current, is a more powerfull tubes max 50mA not 30mA like a E 280F. Thats change the sound totaly .idle operation~ 30-35mA

 

[mitch2+]

In my system with the Helene, the more negative (-260) you go, all the adjectives improve (clarity, separation, imaging and sound stage). Less negative (-220) all the adjectives seem to lesson and I suppose the sounds goes a bit warmer. Warmer isn't what is predominate compared to the adjectives. I'm running with E280F and the GE/Matsushita GZ34 rectifier

I finally had time to listen with the top off so I could easily try different bias settings. What you said above is exactly what I heard. It doesn’t seem to be about warmth vs. detail but rather about finding an optimum setting for the specific tubes being used. In the extreme, it seems too high a setting (ie., a smaller negative number like -220) sounds muffled while too low a setting (i.e., approaching -280) causes the sound to thin out and become a touch brittle - that’s what I heard anyway. I settled in at -255 (for now) and it sounds much better than at -220.
Thankfully, I have a couple of pairs of E280Fs, a pair of E810Fs (didn’t like those as well), and just purchased two pairs of Russian 6J11P-Es, which were dirt cheap.

So far, compared to the other DAC in my main system, the AC Helene seems to provide improved clarity, an expanded soundstage (width and depth), more extended and slightly smoother high frequencies, and slightly better defined and deeper bass. The other DAC has very nice tonality (matched by Helene), an appealing underpinning from the mid-bass on down, and a midrange richness the Helene doesn’t quite match. It may sound a little better than Helene on some older and poor recordings.

 

[Synaxis]

This is great info. Thanks guys for sharing your experiences.

 

[Argonaut]

The other DAC has very nice tonality (matched by Helene), an appealing underpinning from the mid-bass on down, and a midrange richness the Helene doesn’t quite match. It may sound a little better than Helene on some older and poor recordings.

Referencing specifically your consideration regarding the midrange performance from your Helene , the DAC will continue to mature in that regard with incremental hour on the clock , Is your Helene relatively new ?

I would recommend sourcing a pair of Valvo E280F (Philips factory) as per my previous post and considerations therein :

Kassandra II Ref E280F options

I like to have spares for all my vacuum tubes and the last to source are for the Kassandra Ref II. Stavros, do you have any tips for purchasing E280F spares? Do you supply them? What should I look for when purchasing, measuring and matching? All incoming tubes are tested and traced on my...

www.whatsbestforum.com

The power supply sported by Helene is very well implemented however the DAC does respond to a very good power cable/connector combination.

 

[mitch2+]

Referencing specifically your consideration regarding the midrange performance from your Helene , the DAC will continue to mature in that regard with incremental hour on the clock , Is your Helene relatively new ?

I would recommend sourcing a pair of Valvo E280F (Philips factory) as per my previous post and considerations therein :

Kassandra II Ref E280F options

I like to have spares for all my vacuum tubes and the last to source are for the Kassandra Ref II. Stavros, do you have any tips for purchasing E280F spares? Do you supply them? What should I look for when purchasing, measuring and matching? All incoming tubes are tested and traced on my...

www.whatsbestforum.com

The power supply sported by Helene is very well implemented however the DAC does respond to a very good power cable/connector combination.

Thanks for the comments. The DAC itself is 4 years old. It had new stock (used but not NOS) Mullard tubes in it and I have purchased a few pairs/types of tubes to try but not yet the Valvos. I currently have installed the NOS Siemens E280F tubes that AC recommends. I found NOS Valvo E280Fs (from Germany, assume the Phillips factory) but I am hesitant to spend $300 on more tubes, even though the changes that you described in your post (with Valvos) would move the sound in the direction I am looking for.

Regarding power cords, I am interested in what people mean by a "very good power cable." On these forums, it seems many associate the quality of a power cord with the brand name and price, but I am curious which factors actually influence the sound - wire gauge, geometry, shielding, metallurgy, connectors, insulation, or something else - IOW, what makes a PC sound very good?

I currently power the Helene using a 7awg per pole power cable made from old stock Western Electric (tinned annealed copper) wire in a star-quad configuration to reduce inductance and electromagnetic/magnetic interference. The cable is shielded and the ground is also 7awg spiraled outside of the shield. It has Furutech connectors. The PC is routed through the "digital" outlet of an Isoclean 60A3 II filter connected by an Isoclean Super Focus power cable to a Furutech GTX-D duplex power outlet fed by 10awg Romex from a dedicated 20A circuit. I do have some other PCs here I can try but other than the gauge being larger than necessary, it seems that the cable I am using should serve the intended purpose. I could also try it connecting it directly to the wall outlet, as I do for my amps, although the Isoclean 60A3 II has not displayed any negative effects on the sound of the other front end gear that I have used it with.

I also looked into the fuses. Surprisingly, I could find nothing in the AC Helene manual or on their website regarding the fuses. Based on my on-line searching, it seems the line fuse could be a 2.5A and the internal fuse may be 1A. In the Helene DAC I have here, I found T3AL 250V standard glass line fuses in the IEC/fuse holder and have not yet checked the internal fuse(s). I would like to try some Furutech 5A fuses that I already have here in the line position, but those may be a little too big to provide adequate protection so I will look into purchasing some upgraded 3A fuses. Have any of you seen documentation of the proper replacement fuses for the Helene?