Darkvoice just released 332 - Page 12

The 332 takes an age to burn in: at least a couple of hundred hours. My initial impressions: harsh and brittle top-end, slightly lumpy and congested. But it opens up and smooths out as it runs in. Higher quality tubes are the answer, and basically anything is better than the stock 6J1s. Awful tubes. Strange how they can build an amp as good as the 332 yet they can't build good, audio quality tubes.

Correct me if I'm wrong, but I don't think there has been any experience of hum emanating from the stock 332, not on this froum anyway. There has been some experience of hum during tube rolling. This may go away as the amp burns in. But replace the stock tubes and really hear the 332 sing.

Hum is getting quieter pretty quickly as I am letting it run, so thats cool.
Any comments on Svetlana 6S19P-V tubes? (military stock).

I also tried to find some of the black-plates u mentioned - hard to find :-/
Looking around at other options for the moment. (siemens tubes go pretty cheap for the preamp tubes, should I? xD)

Gah I prolly should read more but in general, what tubes can I and what can't I use?

The Svetlana Tubes are very good, a big improvement over the standard 6S19s. There're very "valvey" - bags of presence, open and warm with plenty of detail. The Ulyanovsk version of the 6S19P-Vs is better: bit less warm, more detail with great separation. There's no real choice in this area, apart from these two brands - either the 6S19P or the better quality 6S19P-Bs.

Basically, any of the smaller, output tubes is better than the 6J1s. The Russian equivalents are always good to try - 6J1P or the 6J1P-EV. The western equivalents are also excellent. Try 5654s, add a "W" or "SQ" for special quality mil-spec versions. Black Plates are usually military valves with very durable, low corrosion plates. Then there's the 6AK5, again add "W" for higher quality version. The MULLARD M8100s are superb, which is a mil-spec version of the EF95; there's also a EF95F. Other British mil-spec types have the prefix "CV" meaning Commom Valve. Try CV4010 or CV850. Other types are 6F32 and 403A, but personally I've not come across them.

Haven't heard the SIEMENS, but judging by tubes I've heard in the past they should be excellent.

How does the Darkvoice campare with WooAudio?

Eh, I heard it was the shipping that kills the prices of these Darkvoice amps. How heavy is the 332?

6 pounds or so. Shipping is 80 bucks cause they ship via air, it seems to be a common thing amongst all Chinese sellers. (not sure why).

So far it is still definitely worth it, its pleasant from the start and slowly opening up as I left it overnight to burn in. Did not get the harsh highs others mentioned (although hd595 is rather mellow about things).

Thanks for the excellent reply Godkin.

As for me, when I have no music running through and if I turn the volume up pass 9 o'clock position, I can hear the hum. Not sure if it is just mine or have others experience the same thing. Anyway, at that position, it is way beyond my listening level so it never bother me.

Hrm, mine is volume ignorant, same at 7, 9, 12... ( I am guessing yours is the preamp tube while mine is the power tube).

Gah...ebay is not very friendly when it comes to 6S19Ps...there is a few, but they are sold in batches, and on top of that they are without any measurements. (And I don't have a tube tester obviously...might have to go scout the EE building in my University for one). What do you think, 8 Svetlanas 6S19P-Vs for $19, new. Chances I'll get at least 1 matched pair?

lol....pardon my ignorant but what's a different between the preamp and power amp tubes?

My tube amp sometime picks up radio broadcast. I guess it is from X10 through power line. It is so low, it does not bother me that much. But I still want to get rid of it someday somehow.

Yeah, they seem to sell these tubes in large batches. I think it's because they buy them, obviously from military sources, in bulk.

Personally, I don't think exact matching of tubes in a headphone amp is that crucial. The SVETLANA and Ulyanovsk 6S19P-Vs or Bs are military spec, and as such are made to very stringant tolerances. The differences between any two tubes would be very slight and certainly not audible. Any tubes I've fitted to the 332, which are, technically, not matched, have worked perfectly well.

The 6S19Ps are, to my knowledge, power rectifiers. The smaller tubes, originally used in Ham Radios, are signal amplifiers.

jamesp:
well in headphone amp case its not really important, generally preamp tubes pick up the signal and color it while the power amp tubes bring it up to snuff. (this is the way its done in guitar amps).
I am just using this terminology here since preamp tubes are small, power tubes are large, so we get excellent way to refer to things on the 332 =]. In reference to hum: if its in the preamp stage, the power stage will amplify it, and that part is controlled by the volume knob, if its in the power amp stage, its probably not going to be amplified since its usually present after the gain section.

pftr: I'd try one of those surge protectors with built in noise cleaners, I am waiting for one to arrive to try ^.^ (they are supposed to help out the low end too, making it more controlled and extended ).

Godkin: cool thanks for that suggestion...mebe I'll start looking for matched tubes then =].

So anyone want to split some Svetlanas with me? Ima grab 8 6S19P-Vs.

Aa Malos says, an origin of the hum could be a "dirty" mains source. Try a mains conditioner and a better mains cable. Another cause of hum can be the positioning of inconnects: are important cables, especially digital cables, placed next to a power cord? Of course, it could always be a duff tube, either rectifying or signal.

There appears to be more hum related problems associated with the 336 than the 332. In the case of the 336, hum can be alleviated by the fitting of cathode bypassing caps.