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Old 21st June 2006, 01:20 PM   #101
kmtang is offline kmtang  Canada
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I have both EH and TJ full music 300B's. They sound quite differently but I like them both.

Why not have them all. EH 300B is so cheap.

Johnny
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Old 21st June 2006, 04:43 PM   #102
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Quote:
Would this link help MrAnnan?
Yes! I read this some time ago, but forgot about it.

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BTW, I still stand by anything written
Excellent! The TJ Meshplate it is!

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Why not have them all. EH 300B is so cheap.
Why not ask Mrs. Annan? Mrs. Annan is so cheap.

I'm putting together a list of other parts I'm going to order for your collective review.

Stay tuned and thanks again for all the help!

Kofi
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Old 21st June 2006, 04:52 PM   #103
kevinkr is offline kevinkr  United States
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Hi Kofi,
I have heard the TJ gold pinned meshplate 300B very recently (not in my amp unfortunately) and thought it sounded very good. I too am curious about this tube and am thinking about acquiring a pair at some point.

The KR labs 300B globe with mesh plates is well regarded and even better reviewed than the TJ, however I have not heard it yet. I plan to acquire a new pair by year's end and will report on them when I do. Other KR's I have used have been great.

Currently I use the JJ300B in both my PP amps and my SE amp - in all cases a very good performer.

In the past I have used Valve Arts 300B and Svetlana 300B neither of which was particularly reliable.

Shuguang solid plate 300B neither sounded good nor was it particularly durable.

I thought the SV300B sounded pretty good until I got my hands on some then current production 300B (about six yrs ago) and the WE just cleaned their clock, as do incidentally the JJ I am currently using. I have not been able to compare the JJ to the WE as I no longer have a pair.

JJ is a good everyday use tube, performs well above most of the pack in my estimation, only the KR or WE are likely to be significantly better. Both are significantly more expensive.
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Old 21st June 2006, 05:13 PM   #104
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I have heard the TJ gold pinned meshplate 300B very recently (not in my amp unfortunately) and thought it sounded very good. I too am curious about this tube and am thinking about acquiring a pair at some point.
Another vote for the TJ!

Here's the schematic again, but with some part selections I'm considering. Some questions, as always--

1. How can I get the 60R4 resistor value and what type of resistor should I use here?

2. Would the Kiwame Carbon Films work for the 220Rs? I like them for the precision and I've heard they're nice, but I'd like your opinions.

3. Can I use Mills Wirewounds for the big'uns hanging off the 300b cathode? If so, are there better wirewounds I might consider?

4. Any recommendations on the 100R balance pot?

5. Where the hell do I get off asking such dumb questions?

6. Aren't I ashamed of myself?

7. Aren't I?

I think that Thorsten already responded to my questions concerning the capacitors, but any additional comments on choices here would be appreciated.

Thanks again for all the help,
Kofi
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Old 21st June 2006, 07:30 PM   #105
Gluca is offline Gluca  Italy
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Not familiar with this circuit but ...

1. I believe the amp would not complain at all if you make that R 500 or 820 or 470 ... it looks really like a grid stopper and you want to set that value by ear/oscope. At the end of the day, I just removed the grid stoppers.

2. Cheap tyco 700V 2W carbon resistors (my pick-up for screens/bleeder and minor duties)

3. Thick film planar resistor here (OH! I can't remember the brand)

4. Not from me. Anything >0.5W would do the job.

Caps ... I'd go for paper/oil cap for the main ultrapath bypass

Ciao
Gianluca
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Old 21st June 2006, 11:51 PM   #106
arnoldc is offline arnoldc  Philippines
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Hey Kofi, for the 100R pot I used one of these - Precision 100R/3W - 1316849, Wirewound 10R/3W - 1054922. Part numbers from Farnell.

For the 300B, I guess you're the only one who can say what you like. I've heard a OEM China 300B (which I would guess as Valve Art) in my amp (what I own), the TJ baloon mesh (perforated) plate, new production WE300B.

What I can say is that there is audible differences between the 3 of them. Will I spend that much for a WE300B? Maybe if I had the money. I find the TJ a bit slower, mellower than my generic. All three were used in my amp.

For the ultrpath cap, I'd say the Obbligato, but I guess even their "john holmes" is not enough- just 30uF. I don't know if T would agree to just 30uF.
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Old 22nd June 2006, 10:15 AM   #107
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Hi Kofi,

Good to see that you are making progress on your project. I´m also almost ready to start building Thorsten´s phono pre...we´ll be brothers in equipment over the athlantic!

Let´s see. These are the parts that I used on my amps:

47K input resistor: Caddock TF020. I think this resistor is really important for sound quality so the best you can use over here. I guess tantalum would be also good.

60R2: This is the value of the 1st grid stopper resistor that I used on the amp. It was a caddock unit. Good sound but I have later replaced it with a nos 100R 1/8W Bradley. Not a big difference, maybe more of a natural sound with it.

220R: Generic 1/4W metal units. No clue if using "boutique" parts would be of any use here...help anyone?

12W and 9W Resistors: I use Mills wirewound. Maybe I´ll try Caddock Mp-930/925 soon to see if they bring some benefit.

100R pot: Vishay 1280G

100R and 10R next to the pot: Dale 1W

For the WE conections caps I settled with the following combo for it´s sound:

- 50uF and 15uF: Ducati plastic Motor Run
- 3,3uF and 1 uF: Solen MKP
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Old 22nd June 2006, 10:20 AM   #108
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Let´s continue:

220nF and 68nF: Multicap RTX
15nF and 4,7nF: 500V Silver Mica

Hope that this helps a little bit. By the way, the Silver mica caps made a big difference in clarity. Make sure you use those.

I have only used TJ punched plater. Haven´t compared it to any other 300B BUT I have heard very good things on the Emission Labs and KR. No complaints on the TJ so far though.

Keep us posted please. What speakers are you going to be using with these amps?

Best regards,

Luis
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Old 24th June 2006, 04:02 AM   #109
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Sorry for the delayed response...

Quote:
I believe the amp would not complain at all if you make that R 500 or 820 or 470 ... it looks really like a grid stopper and you want to set that value by ear/oscope. At the end of the day, I just removed the grid stoppers.
Cool. Good to know there's some play in the gridstoppers. I think that the gridstoppers are to prevent the grid from drawing current (right?), but I'm curious to know why you might have more play in this resistor's value over the 47K input job.

I'm NOT challenging this here-- I am really stupid enough to not know.

Quote:
For the 300B, I guess you're the only one who can say what you like. I've heard a OEM China 300B (which I would guess as Valve Art) in my amp (what I own), the TJ baloon mesh (perforated) plate, new production WE300B.

I find the TJ a bit slower, mellower than my generic. All three were used in my amp.
Good to know. I don't mind trying a few, so it's good to know that price is not necessarily a factor.

Quote:
Good to see that you are making progress on your project.
Bought a couple of transformers off a barnacle in Las Vegas and some aluminum. Wheee.

Jack's the greatest, really. But if you've talked to him, you know what I'm talkin' 'bout!

Quote:
47K input resistor: Caddock TF020. I think this resistor is really important for sound quality so the best you can use over here. I guess tantalum would be also good.

60R2: This is the value of the 1st grid stopper resistor that I used on the amp. It was a caddock unit. Good sound but I have later replaced it with a nos 100R 1/8W Bradley. Not a big difference, maybe more of a natural sound with it.

220R: Generic 1/4W metal units. No clue if using "boutique" parts would be of any use here...help anyone?

12W and 9W Resistors: I use Mills wirewound. Maybe I´ll try Caddock Mp-930/925 soon to see if they bring some benefit.

100R pot: Vishay 1280G

100R and 10R next to the pot: Dale 1W

For the WE conections caps I settled with the following combo for it´s sound:

- 50uF and 15uF: Ducati plastic Motor Run
- 3,3uF and 1 uF: Solen MKP
Well, I like the Caddock idea. They look like the sort of resistors you'd see in The Matrix.

Quote:
I use Mills wirewound
I like those fine.

Quote:
What speakers are you going to be using with these amps?
Got some Fostex 206Es in a backhorn. I like them a lot, but I need to re-box in an ML-TL.

I need to add photos of the huge transformers Jack wound for me. If these got into the wrong hands...

Kofi
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Old 21st July 2006, 04:36 PM   #110
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Hello all. For the Thorsten 300B. Is there an original thread or link on the web that provides more information on it?

Thanks in advance.
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