[ScottID]

The problem has nothing to do with my music source. It has to do with power -> amp -> headphones. I just tried the Furman AC-215A - huuuuuuummmm. I don't know what else to do:

• Different tubes (Electro Harmonix, Mullard, Amperex) = hum
• Different headphones = hum
• Different outlets = hum
• HumX = hum
• Forman power conditioner = hum

Is this something I need to live with? Should I give up on the Feliks and try a different brand?

I'm very disappointed as I was looking forward to getting into tubes; however, I must say that my first foray has been nothing but bitter disappointment, unless 'hum' is what it supposed to be...

 

[ScottID]

I had posted my issues on a different audio forum and member suggested that perhaps the toroidal transformer may be the culprit. He suggested rotating the transformer to re-direct the EMF. He mentioned that rotating toroidal transformers is common practice for reducing hum in phono setups. Anyone ever try this?

Out of random curiosity, I whipped out my trusty EMF reader and it pegged the needle as soon as I was within 3-4 inches of the transformer. I also picked up high readings off the tubes themselves (although this could have been residual readings from the transformer).

The next question: would some sort of Faraday screen help? A copper mesh around the toroidal transformer and around the tubes themselves?

 

[mattrudy80]

I had posted my issues on a different audio forum and member suggested that perhaps the toroidal transformer may be the culprit. He suggested rotating the transformer to re-direct the EMF. He mentioned that rotating toroidal transformers is common practice for reducing hum in phono setups. Anyone ever try this?

Out of random curiosity, I whipped out my trusty EMF reader and it pegged the needle as soon as I was within 3-4 inches of the transformer. I also picked up high readings off the tubes themselves (although this could have been residual readings from the transformer).

The next question: would some sort of Faraday screen help? A copper mesh around the toroidal transformer and around the tubes themselves?

Hmm. Very interesting. Working with faraday cages in the past, I know they would shield against RF noise. You could give it a try. One thought - if this is the only known instance of this happening, I would go out on a limb and say that would theoretically be a manufacturer defect. Unless, however, the transformer is fed dirty primary power. Would that equate to high EMF noise or would it be gone by the time it hits the secondary? Dang, you got me thinking...

 

[tracyca]

Sweet sound of tubes! This evening me and the dt1990 pros are loving the tong sol 2c51 black plates Dgetters. I need to explore the 5670 type tubes more often. Really dynamic theses tubes bass is slamming and lots of air on top. Nice tube.

 

[tracyca]

Around a hour ago I recieved a pair of Salvania gold brand 5670 grey plate D getters tubes! No noise and sounds as good as the tong sol 2c51 black plate D getters out the box. Give it some breaking in and I will report back.

 

[ostewart]

I still use my Expressivo MKII regularly, love it so much.

 

[tracyca]

I also love my espressivo mk2, these 5670 tubes really are special. Only if I would of listen to your recommendations Ostewart my money would be stacked. 6922 tubes are not bad by no means. I prefer 5670 sylvania Gold Brand gold tip.

 

[tracyca]

Western Electric jw 2c51 in the house!

 

[ScottID]

I've been rolling like a madman: Amperex 7308s, and Matushita 7DJ8s. Both of those are really nice. I'm also waiting on Siemens E88CC / 6922 A-Frame Getter, and BEL E88CC / 6922 (similar to Philips SQ). I'm going nuts!!

 

[tracyca]

Tube rolling is fun, have you rolled any 5670 tubes with adapters?

 

[ScottID]

Tube rolling is fun, have you rolled any 5670 tubes with adapters?

No, I haven't done any of the 5670s - where are you finding these? I've been living on UpscaleAudio and AudioTubes...

 

[tracyca]

Upsacle Audio don't sell any, but Audio tubes.com does. Just purchased a pair of we 396A from them. Ebay is where I buy most.

 

[tracyca]

 

[mattrudy80]

I've been rolling like a madman: Amperex 7308s, and Matu****a 7DJ8s. Both of those are really nice. I'm also waiting on Siemens E88CC / 6922 A-Frame Getter, and BEL E88CC / 6922 (similar to Philips SQ). I'm going nuts!!

Did you ever figure out the source of your noise issue?

 

[ScottID]

Did you ever figure out the source of your noise issue?

Yeah, I did: Mullard E188CC tubes! I tried many different things to try and quiet down the Mullard hum: HumX, power conditioner, copper crowns... nothing worked, so I moved on. I got a pair of Amperex 6DJ8s and some super sweet 7308s. The Matushitas were also super sweet (apparently there is an AI on this forum that stars out 'bad' words, so read the stars as 'sh..'). I really wanted those Mullards to work, but alas, it was not possible... I did a lot of reading and zeroed in on Amperex and Philips for a similar sound. Apparently, the BEL E88CC is supposed to be the same as the vaunted Philips E88CC - just assembled in India instead of Holland for a cheaper price.

I am still holding out for Mullard! If anyone knows where I can source some Mullard CV2493/6922 (or other Mullard suggestions), then I am all ears!