- #191 [JCR33], 07-03-24 11:16
- #192 [MatthewC], 07-03-24 19:37And these are black based/black plate fat bottle CV378.
Ze best :-) - #193 [ptsang], 07-03-24 22:11Mat, are these branded Cossor, best of the best.
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- #194 [MatthewC], 07-03-24 22:34Of course.
- #195 [MatthewC], 07-05-04 10:36ptsang hing,
Just wondering about your experience w/ using different 6X4 and 5687....
I saw some Genelex U707 available, as well as Bendix 6900. These are very expensive, but don't know if they are worth the price of admission....
Thanks! - #196 [lau60385577], 07-05-04 11:08Hi All,
Bendix 6900 called super 5687...but many people try such 6900 in their AN's gear have no wonderful result, 高音有D拮耳, 不過低頻表現十分好, the c/p is not high...The price is so high due to very rare in the market! I tried 50's Tungsol 5687 Square Getter Black Plates, the best 5687 i heard.
For 6X4, GEC CV4005 is great! - #197 [lau60385577], 07-05-04 11:09Bendix 6900
- #198 [lau60385577], 07-05-04 11:12(6900=ruggedized premium grade variant of 5687 with superior sonics, punchy lively sound)
(6900 is also better sonically than a 7119 Amperex Holland PQ)
(7044 is an excellent substitute for the 6900 at a cheaper price)
One NOS Gold Pins Bendix 6900 cost around USD$300 ~ 450 - #199 [MatthewC], 07-05-04 14:43Thanks Lau hing. I have a pair of 6900 (not the gold pin one) on order. Someone on the net mentioned that it mates well w/ 845 (and maybe 211? Dunno). Will find out.
On a separate note, dunno if thera are any Kondo owners here who knows the functions of the 12AT7 in the M7's. My M7 uses 12AY7/6072 and 12AT7. However, I was advised that the 12AT7 is for the Low Pass ouput and thus has no real function if only the full-range output is used. I would like to unplug the 12AT7 in this case.....
F2aYeung hing? Peter? - #200 [F2aYeung], 07-05-04 16:10Matthew hing,
Imho, the HV of M7 is not regulated. If you unplug the two 12AT7, probably the HV will rise due to the 'decreased load' which might not be healthy for the two remaining 6072.
Btw, does your M7 come with this expensive ALPS RK50?
http://cgi.ebay.de/ALPS-Super-High-End-Potentiometer-RK50112-RK50-TOP_W0QQitemZ260072320865QQihZ016QQcategoryZ12078QQcmdZViewItem - #201 [MatthewC], 07-05-04 17:12F2aYeung hing,
My M7 IIk does come with the potentiometer. Actually I bought the balanced version when I was in Tokyo a few months back!
Do you know if the LPF out is indeed driven by the AT7? I am just wonder if I should plug in something nice (like my TFK 801.....) - #202 [F2aYeung], 07-05-04 17:26I'm 90% sure they are used for the LPF only.
If you look at the circuitry of old M7 tube and M77, the line stage is identical.Standard 2 stages 6072.
There is no need for an extra 12AT7 double triode stage for a line amp.
Does your M7 come with this type of 'air-sealed' resistors?
These are the best type used in Kondo preamps. - #203 [drwkng], 07-05-04 17:32Does your M7 come with this type of 'air-sealed' resistors?
----------------------------------------------
the air sealed is probably there to prevent the carbon comp from absorbing moisture. right? - #204 [MatthewC], 07-05-04 17:38I don't quite remember if the resisters looks like this or not. Will check....
- #205 [MatthewC], 07-05-04 22:42F2aYeung hing,
No my M7 IIK's resister doesn't have those seals. I wonder how the sound compares..... - #206 [F2aYeung], 07-05-04 22:47I think the seal is more for the silver wirings to prevent oxidization.
Those should be tantalum resistors and the legs were all cut and replaced by silver wires.
Only those batch produced right after Kondo split apart with ANUK were installed with this type of resistors. You can imagine the labour involved to solder and seal all these resistors! - #207 [MatthewC], 07-05-04 23:20That's interesting. Looking at the stuff inside, some of the parts are made in year H10, which I think denotes Heisei 10th year, which 1998. Just some tid bit of history.
After retubing the M7 IIK w/ GEC CV4005 and RCA 6072, I settled down for a quick listen. While the sound is stilling opening up, my previous issues with volume seems to be solved. I can now have the exact volume I want (versus the Ongaku's stepped volume), and I can listened at even lower volume, and the sound is still great. I am happy :-)
Regarding the 12AT7, I am still intrigued. The current M7 also uses the 12AT7 (i.e. both 5687 and 12AT7, even without Low Pass Filter output). Hmm. - #208 [F2aYeung], 07-05-04 23:43If you look at this site
http://www.blackforestaudio.de/cms/front_content.php?idcat=100
M7-Line has only two tubes.
Only M7-Phono and M7 has 4 tubes and the latest version has Tesla ECC802 + ECC803 tubes for both models.
There is also the M7IIK Signature with 6 tubes (2 X 5751 + 2 X 12AT7 + 2 X 6072). - #209 [MatthewC], 07-05-05 08:08You are absolutely right, F2aYeung hing. That's even better as I don't need to spend on the 12AT7.
Also spotted a pair of Western Electric 242C, which is a 211 sub, I think? Price is very very steep. Just wondering if any brother has heard them? - #210 [ptsang], 07-05-05 17:53Hello Mat anf F2a hing, the Ongaku problem I reported a few days ago may only be caused by a losen contact in the 211 tube-holder. I checked with KC and confirmed that tube-holder problem is not uncommon in the Ongaku. I run the Ongaku 10 hours a day with the GE tubes, so far, there is no problem, I'll report further.
My fav 6x4 is the Genalex U707, it was made by GEC in the late 50's, there is a test report attached with the tube and the date of the report is 1960, so my best guess is late 50's. I have another U707, the test report has no date on it,but the format of the report is different and paper quality shows later production, though I find no structural difference in these 2 tubes. The older one sounds a bit, only a very little bit better in transparancy and musical presentation. The older one takes longer time to break in,I'm talking about weeks, otherwise it will sound bright and muddy from mid to bottom.This confirms my findings in both the M77 and the Zanden CDP.I did try a 70's CV4005, it sounds good but too hi-fi in my M77, it could be the best match in the M7 in view of the sound signature of the M7.
About the 6072-I love the GE 50's, black plate, triple mica and square getter. The later ones made in 59,60 and 61 are very good too. I bought several pairs from Branden 2 years ago. I use a 50's pair and 1961 pair in the M77, and a pair 1955 in the Ongaku.
About 5687, 50's (1952-1956) Tung-sol is my choice, they are smooth, musical, lots of details and very rich in harmonics, not too thick( the 80's Phillips Jan) and not too thin(50's Raytheon), they just sound right. The 1949-1951 Tung-sol is a different creature, both structurally and the sound, you can ignore it if you treasure correct tonal balance. That's about all I experience with these tubes, cheers. - 下一頁 (10.5 of 39)
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Yes, with Mat's help, I got a set of the Cossar. My initial impression with these tubes are good. We have ordered more and the metal base Milliwatt GZ34 should arrive soon. :-)
I will need your help later on the smaller tubes when my M7 Line and Phono have arrived.