Onix/Melody SP3 - Tubes!!!

[uw69]

What tubes are you using in your SP3?

I'm using Valve Art 350B Power tubes, Stock Melody 6922's, GE 5751 triple mica black plates
RCA 12 AU7 clear tops.

Looking for something to swap out the stock 6922's for...maybe Amperex or Mullard.

[mojave]

12AX7 = GE 6201 3MBP
12AU7 = RCA 5814 2MBP
6922 = Tesla PCC88
Power Tubes = Stock Melody Tubes but I want to get a quad of the Valve Art 350B's

I am listening to my SP3 at work right now with a pair of ELT525M's since my dad is borrowing my Gizmo. I am using a Hsu VTF-1 subwoofer. With my X-Fi soundcard, I use Audio Creation mode and duplicate the front channels to the Center/Sub channel. I then route this to the subwoofer and use the sub's crossover set to 60 Hz to match the natural rolloff of the speakers. This is just a wonderful little setup.

[bunnyma357]

Here's what I currently have:

12AX7 Slot - NOS GE 5751 Triple Mica Black Plates
6922 Slot - Used Amperex USA 6922 PQ's
12AU7 Slot - NOS RFT ECC82
Power - Valve Art 350B's

I've got a bunch of tubes and do tend to swap stuff out frequently.

Jim C

[cedman1]

Currently using stock. Hope to have some VA 350B's soon.

[Kevin R]

Good thread I hope to be getting one soon and have no clue about tubes. It'll be my first so I'm diving into a whole new realm of audio and will be using my fourth bedroom as an office/ listening room. Really looking forward to it.

[uw69]

Here's what I currently have:

12AX7 Slot - NOS GE 5751 Triple Mica Black Plates
6922 Slot - Used Amperex USA 6922 PQ's
12AU7 Slot - NOS RFT ECC82
Power - Valve Art 350B's

I've got a bunch of tubes and do tend to swap stuff out frequently.

Jim C

How do you like the Amperex in the 6922 slot?

[uw69]

Still have tons to learn/explore about tubes. How important is to have a matched pair in a 6922 slot?

[ratracer]

Still have tons to learn/explore about tubes. How important is to have a matched pair in a 6922 slot?

Keep in mind that the 6922 is a triode design which means that you not only have to decide if matching between tubes is important, you also have to decide how important it is for you to use tubes that are individually balanced.

[bunnyma357]

Latest set up is all NOS Russian and East German from eBay, not quite as detailed and airy as the GE 5751, Amperex 6922, RFT ECC82, Valve Art 350B combo. But I think the new set up sounds more dynamic with better transients. Probably a better rock set up than vocals/jazz/acoustic.

Here's the breakdown with approx. eBay prices.

12AX7 slot - RFT ECC81 (12AT7 - 60% gain of a 12AX7) $10-$20 ea.
6922 slot - Reflektor 6N23P-EV $15 ea.
12AU7 slot - RFT ECC82/12AU7 $20 ea.
5881 slot - Reflektor(?) 6P3S-E (Coin Base) $7 ea.

I'm really like the sound of these together, really musical and lively.


Jim C

[uw69]

Wow that some pretty reasonable prices. Glad you are enjoying the sound. Never been brave enough to purchase tubes off e-bay.

[ratracer]

Here's what I currently have:

12AX7 Slot - NOS GE 5751 Triple Mica Black Plates
6922 Slot - Used Amperex USA 6922 PQ's
12AU7 Slot - NOS RFT ECC82
Power - Valve Art 350B's

I've got a bunch of tubes and do tend to swap stuff out frequently.

Jim C

What are you using for the bias voltage on the 350B's?

[bunnyma357]

Wow that some pretty reasonable prices. Glad you are enjoying the sound. Never been brave enough to purchase tubes off e-bay.

I've had nothing but great experiences with eBay purchases, but I'm usually buying cheap tubes, so the risk of getting ripped off is low. It's really cool getting a package of Russian tubes from Russia, with all the cyrillic characters and foreign stamps. I really think the old Russian Military tubes are great values, they're common, well made, and affordable. The hardest part is making sure you are getting the right tube, since some people translate the characters and some don't so for example the same tube can be called a 6P3S-E or a 6N3C-E depending on who is listing it, like the 6P3S-E's below.




Jim C

[bunnyma357]

What are you using for the bias voltage on the 350B's?

I have an SP8/3, so I was running mine at .475 (1.36 on SP3), which is a little lower than what most suggest .487 (1.4 on SP3).

It's important to figure out if you get an SP3 which will have the bias value silkscreened as 1.15V or the newer SP8/3 which will have the bias value listed as .4V.

Most posts in older threads listing bias values, list them based on the SP3's 1.15 bias setting for the stock 5881's. You have to convert the values for the SP8/3's .4V setting.

So the recommendation for the 350B is usually 1.4 on an SP3, so you would use this equation:

(.4 ÷ 1.15) x 1.4 = .487

(Base SP8/3 Bias ÷ Base SP3 Bias) x Suggested SP3 Bias = Suggested SP8/3 Bias


Jim C

[ratracer]

I have an SP8/3, so I was running mine at .475 (1.36 on SP3), which is a little lower than what most suggest .487 (1.4 on SP3).

It's important to figure out if you get an SP3 which will have the bias value silkscreened as 1.15V or the newer SP8/3 which will have the bias value listed as .4V.

Most posts in older threads listing bias values, list them based on the SP3's 1.15 bias setting for the stock 5881's. You have to convert the values for the SP8/3's .4V setting.

So the recommendation for the 350B is usually 1.4 on an SP3, so you would use this equation:

(.4 ÷ 1.15) x 1.4 = .487

(Base SP8/3 Bias ÷ Base SP3 Bias) x Suggested SP3 Bias = Suggested SP8/3 Bias


Jim C

That is all very useful info - I was aware that the original version used the 1.15v bias value but not that it differed in the newer iteration. Thank you.

At least there's one less thing now for me to be scratching my head about while I RTFM. :huge:

[tako_tsubo]

I got in on one of the last SP3 on sale and have paired it up with Onix Ref 1's that I recently did the master ninja crossover change. And this is a very well matched up combo. Deep bass, clear and transparent mids to the high....and very fast.
Since I was ordering some Valve Art 350b from boiaudiotubes, I got some jj/tesla Ecc803s'. The JJ's increased the detail of the mids and smoothened the bass...no real affect on the soundstage.
the 350b's increased bass extension and treble extension too...did not notice the rolloff til I made the change. the soundstage seemed to be more focused and centered...tho not deep.the

I thought that the 12ax7 driver tubes would make the most change. I tried a raytheon 5771 tube but I didn't notice too much of a change...maybe slightly brighter.
So went to the 12au7's. I tried some good russian tubes that was used on my sonic integrity hybrid ( a dared clone) and there was not a significant change from stock. Then I tried a Brimar which I also had for the hybrid...then I tried a nos Telefunken Ecc82... not cheap but wow!!! the mids just jumped out and became more clear...the bass deeper. There seemed to be a higher overall resolution to the sound which was helped by a soundstage that was centered yet having great separation of instruments, and having a 3D presentaion up and deep. The telefunken was my favorite tube running from the dared clone to my Stax energizers...but it will stay in the Onix!