[DecentLevi]

I thought RCA 6FQ7 + EL12 Spez was the best, but not after I tried Voskhod 6N23P + EL39. This is a fabulous and divine sound - effortless liquid sweet tone with ability to portray soundstage, imaging and PRaT of any genre with aplomb finesse! It must be crystal with gold internals and here I can have my cake and eat it too. After all this is a very rare authentic Voskhod 6N23P SWGP with CCCP logo. Many fakes abound, several of which I compared it to unfavorably, and the real version go for around $500 each these days, luckily I got mine a few years ago with a bit lower price. Makes the former pair sound muddy and mid-fi by comparison. Of course thanks also goes to our brilliant amp designer Tomas as well. Who would've thought something so small would yield such a BIG amazing sound!

 

[Capunk]

Quick question for the oblivion user with pre-amp built-in,
With stock tubes, the humming noise out of my speaker is unbearable, very audible, is this normal?


This is my setup :
iFi Gryphon -> Balanced XLR output -> Oblivion -> Pre-amp out XLR -> M-PWR Power Amp -> KEF 150

 

[UntilThen]

Quick question for the oblivion user with pre-amp built-in,
With stock tubes, the humming noise out of my speaker is unbearable, very audible, is this normal?


This is my setup :
iFi Gryphon -> Balanced XLR output -> Oblivion -> Pre-amp out XLR -> M-PWR Power Amp -> KEF 150

Don't know. Check with Tomas. I don't have preamp out but I have speaker out and there's no noise at all. So Oblivion direct to speakers.

 

[UntilThen]

I tried Voskhod 6N23P + EL39. This is a fabulous and divine sound - effortless liquid sweet tone with ability to portray soundstage, imaging and PRaT of any genre with aplomb finesse!

That combination will be great for tight hard hitting bass and great overall.

 

[SonicTrance]

Quick question for the oblivion user with pre-amp built-in,
With stock tubes, the humming noise out of my speaker is unbearable, very audible, is this normal?


This is my setup :
iFi Gryphon -> Balanced XLR output -> Oblivion -> Pre-amp out XLR -> M-PWR Power Amp -> KEF 150

It shouldn't make any noise whatsoever. Does it hum when using headphones? If not, there's something going on with your other stuff. The Gryphon has a built in amp, use a low volume here to not overdrive the 6AT6 input stage in Oblivion. Then no more than half volume on Oblivion to be safe. It's all in the manual. Perhaps you have the SE switch ON? If so, flip it to balanced.

 

[Xavilaw]

Quick question for the oblivion user with pre-amp built-in,
With stock tubes, the humming noise out of my speaker is unbearable, very audible, is this normal?


This is my setup :
iFi Gryphon -> Balanced XLR output -> Oblivion -> Pre-amp out XLR -> M-PWR Power Amp -> KEF 150

I have a Citadel (impressions coming in soon) and use it as a pre amp for many situations. I power my KEFQ100 with them. When i first got it i had a bit of noise in the background which was resolved by getting a better power cable for the Citadel and noise gone. Also had to plug the citadel directly in a power outlet on my wall. I also have my Citadel as far as possible from other electronics (PC).

 

[Capunk]

It shouldn't make any noise whatsoever. Does it hum when using headphones? If not, there's something going on with your other stuff. The Gryphon has a built in amp, use a low volume here to not overdrive the 6AT6 input stage in Oblivion. Then no more than half volume on Oblivion to be safe. It's all in the manual. Perhaps you have the SE switch ON? If so, flip it to balanced.

Yes, the noise floor is noticeable with my HD800 (even on low gain), and "obviously" with IEM (pointless but just to demonstrate the noise is there),
I got furutech power cable and power conditioner board, and have tested this with switch up (SE mode) and switch down (BAL mode).

Normally I use Gryphon line out directly to Power Amp with no hum nor noise audible enough (via Balanced XLR) and previously used Burson 3XP as pre-amp without issues as well. Both of them are solid state.

I'll try to isolate the setup and monitor my findings.

 

[UntilThen]

Yes, the noise floor is noticeable with my HD800 (even on low gain), and "obviously" with IEM (pointless but just to demonstrate the noise is there),
I got furutech power cable and power conditioner board, and have tested this with switch up (SE mode) and switch down (BAL mode).

Normally I use Gryphon line out directly to Power Amp with no hum nor noise audible enough (via Balanced XLR) and previously used Burson 3XP as pre-amp without issues as well. Both of them are solid state.

I'll try to isolate the setup and monitor my findings.

Do you have a dedicated dac to try with Oblivion. I have Bifrost 2, Yggdrasil and NAD M51 and I've never had any noise whatsoever with Oblivion. My setup here is surrounded by PCs. I use ordinary power cords and have no power conditioner. Yet I have no noise at all. From both Odyssey and Oblivion.

 

[SonicTrance]

Yes, the noise floor is noticeable with my HD800 (even on low gain), and "obviously" with IEM (pointless but just to demonstrate the noise is there),
I got furutech power cable and power conditioner board, and have tested this with switch up (SE mode) and switch down (BAL mode).

Normally I use Gryphon line out directly to Power Amp with no hum nor noise audible enough (via Balanced XLR) and previously used Burson 3XP as pre-amp without issues as well. Both of them are solid state.

I'll try to isolate the setup and monitor my findings.

Was it you that ordered a bunch of replacement tubes with your amp? If so, try different ones. I obviously tested each one on my tester but not all in circuit.

 

[UntilThen]

Holy moly this amp is huge for my already cramped desk!

Since this is my first tubes amp in decades, is it normal to have the tubes pin not completely pushed in? I was afraid to break the tubes in process? Kinda wobbly but it’s work.

Is it possible your driver tubes are not sitting in correctly. From the picture, it looks like it's hanging loose.

 

[Capunk]

Do you have a dedicated dac to try with Oblivion. I have Bifrost 2, Yggdrasil and NAD M51 and I've never had any noise whatsoever with Oblivion. My setup here is surrounded by PCs. I use ordinary power cords and have no power conditioner. Yet I have no noise at all. From both Odyssey and Oblivion.

I got Denafrips Ares II connected to Oblivion right now (Balanced), I've also used iFi idefender just in case.

Was it you that ordered a bunch of replacement tubes with your amp? If so, try different ones. I obviously tested each one on my tester but not all in circuit.

Wasn't me, but I'll ask my fellow oblivion user here to lend me their tubes.

Is it possible your driver tubes are not sitting in correctly. From the picture, it looks like it's hanging loose.

I've fixed it, and pushed in just as you tell me before.


I'm planning to isolate the amp in a controlled and less busy environment, reshuffle the tubes and see how it goes.

 

[UntilThen]

My HD800 right now is lovely with Oblivion and it's pitch black background. I'm really trying to understand where all these noise issues are coming from lately.

 

[UntilThen]

I've Yggdrasil feeding Odyssey and Oblivion. Susvara is connected to Odyssey and HD800 is connected to Oblivion. I've a lot of electronics on this large desk. Both setups are quiet. After spending quite a lot of time with Susvara and Odyssey (which I think is amazing), I was equally pleased with HD800 and Oblivion. Could be the best amp for HD800.

 

[Magol79]

@Capunk

My desktop computer is running an AIO watercooler. It has a pump running constantly. My tube amp is sitting on the same desk. I had hum problems with several tube pairs. When I put dampening feet under the 'puter almost all hum problems went away.

The situation may be different here. But if anything requiring active cooling is sharing the same desk space as your tube amp, physical dampening may be necessary.

 

[UntilThen]

Step into my world of organised mess and very quiet system.

Frontal shot. My beloved Axis Voicebox S speakers.


On the left.


On the right.