[DecentLevi]

Today my 20A voltage regulator arrived. The previous one I used was rated 15A but not strong enough to handle the Quarter Pounder power tubes - the Cetron 6336B.

https://www.ebay.com/itm/DC-300W-20...tep-Down-Converter-Voltage-Buck/222637386210?
hash=item33d638e9e2:g:K18AAOSw6Q1ZsRox

(There are many sellers - I paid $8.10 for mine and it arrived in a very short 12 days)
It appears that this voltage converter made a difference - the sound is improved. The prodigious bass is immediately noticeable.
So far I just tried it out with an eye on how hot the heat sinks get. The heat sinks are roughly twice as large as on my old 15A voltage regulator - 1" high, 3/8" thick and 1 3/4" wide. I put the converter near my 4" cooling fan, and the temperature does not exceed 100F and there is no danger in touching the heat sink fins (not something I can say about the 5A Cetrons).

The driver tubes are TFK EL11 - nice, vivid and impactful presentation, but need more time to arrive at conclusions.....
Have fun!

Wow Mordy, you're a die-hard innovator. I would really like to hear a comparison between Cetron 6336B vs. your other top chosen power tube setups, when you have time. No need for an in-depth analysis, just sound impressions the way you hear it... though if you can also include headphones for the comparison that would be super, because I'm finding some of your recent suggestions to sound different on headphones than you probably hear it using speakers.

PS - which adapter are you using? And I take it that setup plays nice with "Mr. Humphrey", right?

 

[mordy]

Wow Mordy, you're a die-hard innovator. I would really like to hear a comparison between Cetron 6336B vs. your other top chosen power tube setups, when you have time. No need for an in-depth analysis, just sound impressions the way you hear it... though if you can also include headphones for the comparison that would be super, because I'm finding some of your recent suggestions to sound different on headphones than you probably hear it using speakers.

PS - which adapter are you using? And I take it that setup plays nice with "Mr. Humphrey", right?

Hi DL,
I draw my inspiration from the Glenn Super 9 OTL which has six power tube sockets. Owners have reported very good results using two 6336 tubes and a driver.
The adapter I use is especially made for the Feliks Elise/Euforia by Mrs Xuling and has room for 6 octal tubes. It requires an external power source. I use a run-of-the mill 450W PC power supply that I had as a spare. Then connect the 12V lead to the 20A voltage regulator and setting it to 6.3V. (The previously used voltage regulator was rated at 15A but did not have enough juice for these 10A worth of tubes and sounded hollow.)

The 6336 tubes get amazingly hot. I measured 127C/260F internally in one spot with an infra red thermometer.
This time all my listening has been using headphones: T1 and my favorite, the Senn HD650.
What stand out soundwise is the extremely detailed and powerful bass and sub bass. Some time ago I borrowed a grandson's LCD3 headphones, and this presentation reminds me of that type of bass sound signature.
Re hum; yes, this setup has hum at ear splitting listening levels, but I never need to set is so loud. At normal and loud listening levels I cannot hear any hum. Setting the Euforia volume control at 9 o'clock is plenty loud; the hum only kicks in at around 2 o'clock (with headphones).
Really surprised how good this sounds.....For this experiment I picked two odd 6336B tubes: a Raytheon (less reinforced internal construction than the Cetron) and a used Cetron. Haven't yet tried one of the three matched NOS pairs I have.......

 

[mordy]

Hi DL,
I draw my inspiration from the Glenn Super 9 OTL which has six power tube sockets. Owners have reported very good results using two 6336 tubes and a driver.
The adapter I use is especially made for the Feliks Elise/Euforia by Mrs Xuling and has room for 6 octal tubes. It requires an external power source. I use a run-of-the mill 450W PC power supply that I had as a spare. Then connect the 12V lead to the 20A voltage regulator and setting it to 6.3V. (The previously used voltage regulator was rated at 15A but did not have enough juice for these 10A worth of tubes and sounded hollow.)

The 6336 tubes get amazingly hot. I measured 127C/260F internally in one spot with an infra red thermometer.
This time all my listening has been using headphones: T1 and my favorite, the Senn HD650.
What stand out soundwise is the extremely detailed and powerful bass and sub bass. Some time ago I borrowed a grandson's LCD3 headphones, and this presentation reminds me of that type of bass sound signature.
Re hum; yes, this setup has hum at ear splitting listening levels, but I never need to set is so loud. At normal and loud listening levels I cannot hear any hum. Setting the Euforia volume control at 9 o'clock is plenty loud; the hum only kicks in at around 2 o'clock (with headphones).
Really surprised how good this sounds.....For this experiment I picked two odd 6336B tubes: a Raytheon (less reinforced internal construction than the Cetron) and a used Cetron. Haven't yet tried one of the three matched NOS pairs I have.......

Hi DL,
Glenn says that 6SN7 derived tubes are fine in his amp, so I tried a pair of 6CG7 tubes as drivers with the 6336B tubes.
What could be wrong with a pair of Sears tubes?

These tubes have no markings what they are, but I know I bought them as 6CG7. Made by manufacturer #312. (Sylvania).
How do they sound?

Quite good but, as expected, a little different than the EL11. Need to quantify my impression, but the Cetron bass house sound is there.
What's next? David and Goliath?

 

[DecentLevi]

Yo Mordy, I see you're using a 6BL7 adapter. I've already got two dual 6BL7 to 6SN7 adapters, so I'm thinking I could replace the connection between the heater circuit and the tube by simply unscrewing the adapter and cutting the appropriate wires and instead connecting them to the voltage regulator. I'd just need advise to be certain which two wires to cut, LOL

Your description of the 6336B sounds promising so far, and with the bass described. Would you also have any words about the mids, highs and soundstage? And comparisons to your other favorite power tubes such as RCA 6AS7G or EL12 Spez? I'm actually planning to show my Euforia at a mini-meet in Seattle early next month, and am considering to show your new monster-tube setup... though I would probably want to find some nifty little cover to mask that glaring regulator.

My E-UFO-oria is set up and sounding sublime, but only getting a little head-time as I'm split between a zillion tasks these days, but will report back soon on my experiences too. Thanks

 

[mordy]

Yo Mordy, I see you're using a 6BL7 adapter. I've already got two dual 6BL7 to 6SN7 adapters, so I'm thinking I could replace the connection between the heater circuit and the tube by simply unscrewing the adapter and cutting the appropriate wires and instead connecting them to the voltage regulator. I'd just need advise to be certain which two wires to cut, LOL

Your description of the 6336B sounds promising so far, and with the bass described. Would you also have any words about the mids, highs and soundstage? And comparisons to your other favorite power tubes such as RCA 6AS7G or EL12 Spez? I'm actually planning to show my Euforia at a mini-meet in Seattle early next month, and am considering to show your new monster-tube setup... though I would probably want to find some nifty little cover to mask that glaring regulator.

My E-UFO-oria is set up and sounding sublime, but only getting a little head-time as I'm split between a zillion tasks these days, but will report back soon on my experiences too. Thanks

Hi DL,
Instead of cutting the internals in your adapters I think that you are better off to buy two sockets with the power wires attached for external power.
My favorite combination is GEC 6080 with Foton 6H8C ribbed anodes - don't have the EL12 Spez.
The 6336 has a very detailed bass presentation and the music in the background of soloists is heard very clearly. BTW, the 6336 is a double 5998.
Hard to speak of soundstage since now I am listening to headphones, and I am more used to speakers. Cannot form a detailed opinion on the spot.....lol

 

[Oskari]

I'm actually planning to show my Euforia at a mini-meet in Seattle early next month, and am considering to show your new monster-tube setup... though I would probably want to find some nifty little cover to mask that glaring regulator.

I think your considering showing a more or less standard line-up at meets would be a favour for everybody.

 

[mordy]

I think your considering showing a more or less standard line-up at meets would be a favour for everybody.

Vs

 

[mordy]

VS

 

[Oskari]

It's a bit different when the original is 55+ years old and everybody already knows – has seen and heard – the "standard".

 

[DecentLevi]

Yeah I'd still need a little more research before going the 6336 route, and which brand is more suitable. The adapter mod idea was considering there's not enough time to order adapters from China before next month. If I did show it at a meet, I'll also bring standard tubes also.
PS the 6336 is the same tube used on Zana Deux and must play a good role in that sweet, authoritative sound I remember hearing from it

 

[Oskari]

PS the 6336 is the same tube used on Zana Deux

It is not.

 

[mordy]

It is not.

Hi DL,
The tube used by the Zana Deux is the Russian 6C33C-B 3A tube. The problem all tube amplifier manufacturers face is the availability of tubes in quantity, and the 6336/6528 are too difficult to obtain in enough quantities for a manufacturer.
We lucky tube rollers are not as restricted.......

Switched from the 6CG7 to the Russian Voskhod 6N23P from the 6DJ8 family - sounds good, too.
More forward than the 6CG7 with better bass but slightly sibilant at first listen - will give it more time......
The EL11 has a more even and refined FR.

 

[DecentLevi]

My makeshift temp. tube sorting solution. Not the best, but better than laying tubes flat on a desk to roll around and get scratched. I prefer a solution that lets you view the tubes rather than being in a box or drawer.

Probably a solution like this metal shelf would be perfect, if only the metal was rubber coated.


BTW this is my entire tube collection except for 6BL7 and GE 6AS7G which I don't use anymore... I couldn't be an audiophile who went OCD on tubes, could I?

 

[JazzVinyl]

My makeshift temp. tube sorting solution. Not the best, but better than laying tubes flat on a desk to roll around and get scratched. I prefer a solution that lets you view the tubes rather than being in a box or drawer.


Probably a solution like this metal shelf would be perfect, if only the metal was rubber coated.


BTW this is my entire tube collection except for 6BL7 and GE 6AS7G which I don't use anymore... I couldn't be an audiophile who went OCD on tubes, could I?

Wow, quite a collection, DL...!

Enjoy!!

 

[mordy]

Hi DL,
Very impressive tube collection!
Personally I use old shoe boxes and put labels on them re what's inside. And using plenty of bubble wrap around the tubes.
Re the 6336 tube I think that the consensus is that the best one is the carbon plate Cetron 6336B. You can find Raytheon look alikes, but they have fewer internal support rods. As you all know, more support rods means less microphonics (true/false? - I can't hear the difference).
In my search for the drivers I prefer I am now trying the EL3N. The sound is somewhat similar to the EL11 - a little laid back and sweet. Can't find anything yet that does not sound good with the Cetrons.