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Woo3 Modified - Page 13

post #181 of 242

Wow, NOS... initially

Aloha,

I have acquired NOS tubes and listened. More toobs are yet to come in. No mods on the unit, only toob rolling.

I have an abundance of 6080 and 6AS7G gathering. The better toobs are metal based 6080 for power, but the bakelite base 6AS7G appear to be more open. Surprisingly the 5998 has slightly more bass with lean mids, and some high extension. My favorite toobs are lesser known 6080s or 6AS7Gs.

Interesting are US 6AS7G tubes that are really compressed midgets in straight tubes rather than the ST form or longer tubular envelope. At first glance, I thought these were 6080 tubes owing to their tubular envelopes, but they are short.

The greatest influence on the sonics of the WA3 come from the 6922/6DJ8 or its variants. I used a set of Siemens E88CC, wow... what details and musicality! The next best was a cryo JJ 6922. More variants to listen to and have yet to come in. Realize that I must focus on the factory codes and contruction details to drill in on what I am looking for. The toobs are not really what they are marked as.

Will place a more comprehensive commentary when my toobs are finally in and I begin to do a formal listening.

len

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post #182 of 242
Quote:
Originally Posted by jamato8
The tubes that are the input or driver tubes are the 6922's and the power tube is the 6080. I am using some Amperex PQ A frame made in Holland.... ..But out of all of these some of the best 6DJ8's I have heard are some that are marked Amperex that are Russian from 1982. These tubes are unbelievable and not all that common and often passed by when available. I also like the GE grey glass, an often overlooked tube.
John

The above excerpt from a older post on this forum really intrigued me.


I was able to find a bunch of new RCA 6DJ8 tubes that I like very much. They are marked RCA and UK (British) but are actually Russian tubes disguised as British and as RCA. You can tell by the "saucer" getter found only on Russian tubes.

I wonder if these are the same as the Amperex labeled Russian tubes that Jamato8 liked so much.

Mine certainly sound great.

The Russian 6N23P EB (military) also sound great. I would stay away from the modern 6N23P - if they were not made in the 80s or before they are likely bad sounding.

Don't use the 6N1P - draws too much from the transformer.
post #183 of 242

xfeed Circuit

Aloha,

Was recently sidetracked by looking for a way to alter the sonics of the system without digging to the inside of the HP amp. Came across a simple xfeed circuit of 3 caps, 6 resistors and 4 RCA jacks that could be build as prototype outside of the amp and inserted between the source and HP amp. Was locked into a battle for how to control the noise and humming owing to grounding issues.

Finally, I removed the noise and humming yesterday. The circuit gives an enhanced bass boost with some injection of one channel into the other.... resulting in a more natural soundstage and image much akin to listening to speakers, but with all the details and slam of headphones.

The toobs all arrived, except for a batch from the PRC and Lithuania. Should begin to compare and tube roll after I sort out how to properly implement further refinements of disengaging the circuit from the main system and adjusting the level of crossfeed.

len
post #184 of 242
Quote:
Originally Posted by lglyoung
Aloha,

Was recently sidetracked by looking for a way to alter the sonics of the system without digging to the inside of the HP amp. Came across a simple xfeed circuit of 3 caps, 6 resistors and 4 RCA jacks that could be build as prototype outside of the amp and inserted between the source and HP amp. Was locked into a battle for how to control the noise and humming owing to grounding issues.

Finally, I removed the noise and humming yesterday. The circuit gives an enhanced bass boost with some injection of one channel into the other.... resulting in a more natural soundstage and image much akin to listening to speakers, but with all the details and slam of headphones.

The toobs all arrived, except for a batch from the PRC and Lithuania. Should begin to compare and tube roll after I sort out how to properly implement further refinements of disengaging the circuit from the main system and adjusting the level of crossfeed.

len

so what's the grounding issue? mine hums with certain tubes. so far i've added a power conditioner, cleaned/straightened pins and added some tube dampers... still slightly noisey with some tubes (NOS GE 6BZ7's). I've also built that same crossfeed circuit with matched resistors, but it's external.
post #185 of 242
yotacowboy wrote:

so what's the grounding issue? mine hums with certain tubes. so far i've added a power conditioner, cleaned/straightened pins and added some tube dampers... still slightly noisey with some tubes (NOS GE 6BZ7's). I've also built that same crossfeed circuit with matched resistors, but it's external.

Aloha,

My unit is external also. Some tubes are noisey; can't be helped. My external unit as built from the Rock Grotto site thread had electrical line related random noises and humming. The input RCA jacks are grounded as a floating ground with the middle cap. The output jacks are not grounded... so, I solder the two grounding taps for the output jacks and ran a wire toward the point where the cap leg joined the input RCA jack ground wire. All is silent as a tomb when I fired it up to listen.

My unit was built on a chopping block and plastic panels. If I had used a metal can, it would have been probably silent.

len
post #186 of 242
I've spent a couple hundred dollars on tubes for the Woo3 (I know, I know, you can spend more than that on just NOS Amperex 6dj8's), about 4 different brands of 6922/6dj8's and 5 different power tubes. So far the Groove Tube 6dj8's and the Tungsol 5998's are champs. Any other combo including some Bugle Boys is clearly inferior sounding in my rig, enough so that I just ordered and received 2 sets of spare NOS Groove Tubes and Tungsols for my Woo 3 or maybe I'll buy another one to mod. Cheers!
post #187 of 242
Is 6080 Mullard a good choice for WA3?
post #188 of 242
Thread Starter 
I didn't know they made one. I would give it a shot. What do they sell for and when was it made. I would want something from the 1950's up to the mid 60's. Mullards have a date code on them and a code indicating where they were made. Later Mullards often where from other places as they shut down their factories. What type of box is it?
post #189 of 242
I am new to tubes, so I do not know answers to your questions. I found this listing on eBay:
http://cgi.ebay.com/ws/eBayISAPI.dll...1375&rd=1&rd=1
post #190 of 242
Thread Starter 
That is one of the newer/new type of Mullards and could be anything. I would spend the money. There are many other good tubes on the market.
post #191 of 242
just got one of the Mullard 6080 mentioned above (one week from the UK to California, not bad!). The tube was NIB and has only a few hours on it. Compared to my Cetron/Tungsol 7236 (with perhaps 500 hours on), it is less powerful both on average (I had to turn the volume knob from 9h to 10h to achieve a similar level) and dynamically (the Woo3 sounds a bit more "tubey" now). Highs are a bit rolled off, but they are opening up quickly. Imaging is just as good. Midrange (vocals in particular) sounds sweeter with the Mullard, but it may very well be placebo effect, because I remember the sweet mids of the Mullard ECC88 signal tubes I had on before the RCA/Amperex I use now. Bass goes about as deep but it's perhaps a bit fatter.
In summary I'd say not a bad tube at all, but one that tames a bit the aggressive character of the Woo3...
post #192 of 242
quick update on the Mullard 6080. After perhaps 40 h of use, the slight roll-off of the highs is gone and so is the feeling that the Mullard was less dynamic than the Cetron. I'd say that for the music I listen to (classical, mostly vocal) I like the Mullard better than the Cetron 7236 I had. Good find Mooch2000!
post #193 of 242
Thread Starter 
Do you have an image of the Mullard tube? I would like to figure out who made it. Are there any codes on the tube? Is it a little warmer sounding than the 7236? I find the 7236 in Tung-sol to be more analytical than other tubes but with the combo of the Seimens 6922, it is a nice combonation.
post #194 of 242
not easy to take a picture now, may try that in a week or so.
The tube has painted in white on the front
Mullard
6080
MADE IN
GREAT BRITAIN

and on the back
AJ1
R4C

Other thing I notice is that it has a bakelite base.
post #195 of 242
Thread Starter 
Quote:
Originally Posted by calaf View Post
not easy to take a picture now, may try that in a week or so.
The tube has painted in white on the front
Mullard
6080
MADE IN
GREAT BRITAIN

and on the back
AJ1
R4C

Other thing I notice is that it has a bakelite base.
The AJ is for the tube type 230 which is the Mullard 6880. the R is for Mullard, Mitcham, UK and the 4 is 1964 and C for March of that month.

Nice score.
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