[jambaj0e]

A pair of Japanese Black Plates in the front 2 slots and a pair of Sicte (Italy) in the back 2 slots. These are my two favs out of all of them.

Whoa, I never heard of either of them! Who makes them? Where did you buy them?

 

[Wes S]

Whoa, I never heard of either of them! Who makes them? Where did you buy them?

Yeah, they are quite rare and super hard to find. The black plates were made in the 50's from a factory in Japan, but not sure which one. There were a couple factories in Japan that made tubes for other companies like Raytheon. As for the Sicte, those were made by Sicte of which is said to be a company formed by several workers from Fivre in Italy, after Fivre stopped making tubes.

The black plates do pop up for sale from time to time. However, the Sicte are as rare as they come.

I got all of them from ebay, but unfortunately those sellers sold out of their stock a long time ago.

 

[AudioPowerHead]

Yeah, they are quite rare and super hard to find. The black plates were made in the 50's from a factory in Japan, but not sure which one. There were a couple factories in Japan that made tubes for other companies like Raytheon. As for the Sicte, those were made by Sicte of which is said to be a company formed by several workers from Fivre in Italy, after Fivre stopped making tubes.

The black plates do pop up for sale from time to time. However, the Sicte are as rare as they come.

I got all of them from ebay, but unfortunately those sellers sold out of their stock a long time ago.

No wonder I have no luck in finding the Sicte so far…count myself lucky to have gotten the black plates earlier though.

 

[Wes S]

Anyone looking for some Melz 1578 or RFT 6SN7 Ceramic Plate? I am going to be listing brand new pairs of each that are legit, and test perfectly balanced and they are super quiet as well. Hit me up if you are interested, as I am going to list them in the next few days. I love these tubes, and they are hands down the best 6SN7's ever made, but I am using a different tube type now and have no use.

Just of note, I am only looking to ship within the U.S.

Cheers.

 

[Doctor HiFi]

What's the voltage range you guys use as output from your DAC/preamp to feed your HA-300MK2?

 

[DMITRIY R]

What's the voltage range you guys use as output from your DAC/preamp to feed your HA-300MK2?

2.4 volts on RCA. Everything works without problems.

 

[Wes S]

What's the voltage range you guys use as output from your DAC/preamp to feed your HA-300MK2?

4 volts into balanced and no noise or any issues at all.

 

[Doctor HiFi]

4 volts into balanced and no noise or any issues at all.

2.4 volts on RCA. Everything works without problems.

Thanks for your replies.
I'm asking this question because when I connect my iFi Pro iDSD Signature DAC on HiFi (Fixed) mode (outputting nominal 4.6 V to the amp using XLR connections) I get very very little control on my amp volume knob, meaning that each increase step on my Cayin amp results in huge jumps in volume (even on 300Ω headphones). Besides that, I do not want to overdrive my amp unnecessarily. From what I read on the Cayin amp manual, the listed Input Sensitivity of the amp is 400 mV. I might have understood it wrong though, because it's listed under Speaker Output specs. But that's the only place where Input Sensitivity is listed for the amp.
As a result, I have to use the HiFi (Variable) mode on the DAC and use its volume knob to adjust the output volume. The best listening experience I get is somewhere between 0.5 to 1.2 V depending on the headphone's sensitivity and the type of music. This is in line also with the suggested 3:1 ratio between output and input sensitivity(V) of DAC/preamp and amp, respectively. Have you had a similar experience? Any suggestions or comments?

Regarding noise though, I only get some negligible noise from the power supply, mostly on high impedance setting (regardless of the volume on the amp itself or my DAC/preamp, it's just there), but its level reduces further when the tubes warm up. And I only hear it when there's no music playing.

On a side note, worth mentioning that I've taken it a step further and added my iFi Pro iCAN Signature as the preamp to the chain and to be honest it only provides benefits. No additional noise whatsoever, better perceived soundstage, more weight to the sound in general, and also the lovely analogue xBass and xSpace (3D Holographic) settings at hand when needed, depending on the headphone and the recording/type of music. Then I use the fixed output on the DAC and adjust output voltage using the volume knob on the preamp only. Similar issue exists there too though: I need to keep the volume on the preamp below ~20%-25% to achieve the best outcome (according to my ears at least).

 

[Wes S]

Well it's official. . .I have gone all CV6 and CV1135, as all my 6SN7's (RFT & Melz) have been sold.

Got to love the never ending rabbit hole of tube rolling. . .

 

[JeffMann]

Where do I buy the adapter that Wes features in his Cayin HA300MK 2 amplifier that allows for the use two CV6 tubes to replace a single 6sn7 tube?

Jeff.

 

[JeffMann]

I have found a source of CV6 tubes, but one has to purchase a minimum bulk amount of fifty CV6 tubes, which may be three different types - see attached photo.

Do you recognise the manufacturer of those three different CV6 tubes?

Jeff.

 

[JeffMann]

Here is another tube that I found - listed as a VR135 tube - see attached photo.

Is it equivalent to a CV6 tube? Can you recognise the manufacturer?

Jeff.

 

[ColSaulTigh]

Where do I buy the adapter that Wes features in his Cayin HA300MK 2 amplifier that allows for the use two CV6 tubes to replace a single 6sn7 tube?

Jeff.

I get my adapters from “Mrs. X” on eBay and like them a lot. A user here (@Deyan ) also makes some good ones.

 

[JeffMann]

I get my adapters from “Mrs. X” on eBay and like them a lot. A user here (@Deyan ) also makes some good ones.

Could you please send me a link to Mrs. X on e-bay as I could not find him/her?

Also, are you using the identical adapter as Wes uses - he talks about a version with shorter wires?

Jeff.

 

[ColSaulTigh]

Could you please send me a link to Mrs. X on e-bay as I could not find him/her?

Also, are you using the identical adapter as Wes uses - he talks about a version with shorter wires?

Jeff.

https://www.ebay.com/itm/1934442533...F3JeTGHQaC&var=&widget_ver=artemis&media=COPY

I think Wes modified his himself. You can ask Mrs. X to modify the wires as short as you want. Be sure to rave enough length to be able to slide them on and off the caps and not put tension on them.

@Wes S ?