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 Post subject: Re: KT120 Oddblocks
PostPosted: 14 Jan 2018, 16:54 
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Joined: 29 Mar 2013, 20:37
Posts: 122
Location: Italy
There are so panel meters out there that are on the 100mv / 200mv scale

Image

But yeah i guess they are more useful as "cool factor"


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 Post subject: Re: KT120 Oddblocks
PostPosted: 16 Jan 2018, 06:13 
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Joined: 29 Mar 2013, 20:37
Posts: 122
Location: Italy
mh.. i have read around that newer manufactured kt120 from TS have a lower dissipation and may need a resistor after the grid, can anyone confirm?


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 Post subject: Re: KT120 Oddblocks
PostPosted: 21 Jan 2018, 12:03 
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Joined: 07 Mar 2017, 03:14
Posts: 53
Hi,
Can you give me some alternatives instead of Edcor output transformers? If you advice product and model specific, I'll be very glad.


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 Post subject: Re: KT120 Oddblocks
PostPosted: 21 Jan 2018, 17:40 
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Joined: 04 Jun 2008, 20:59
Posts: 3552
Location: Arizona, USA
Hi, There has apparently been a problem with some batches of Tungsol KT120s. It seems for a while they would not meet the spec for dissipation in class A operation. I have a quad here that miss by about 40%. Really beautiful red anodes. I have KT88s that handle power better. Newer ones apparently are OK. Get them from a reputable source and send bummers back as often as needed to get some that work. Late production 2017 seem OK and ones at least 4 years old are OK as well.

Those meters would look cute, but not be functional. Anything that gets between the two cathodes or between either one of them and the CCS will upset the operation of the amps. It is possible to put some that have relatively low impedance in the anode circuit between the anode and transformer. As long as the resistance is small it ought to be OK. I would switch them out of circuit for music listening. The issue there is that they will be at the B+ voltage. Not something to fool with if not needed IMO. BTW (and stating the obvious for many diyers) the anode measurements would not be the same as the cathode ones as they would not include the screen currents.

Good listening
Bruce

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 Post subject: Re: KT120 Oddblocks
PostPosted: 28 Jan 2018, 15:45 
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Joined: 29 Mar 2013, 20:37
Posts: 122
Location: Italy
Thanks Bruce. I will get my kt120 from tubetown in Germany. I really hope they will be up to the specs

No meters for me then. Too much hassle having them to switch in and out. I will go for the good old testing points

Last question, is it possible to run the blocks in a single case? Separated circuits of course so basically two monoblocks in one case? I plan to make a walnut case and it would really drive costs/ hassle down. The only thing in common beetween the two woulf be the power plug and on/off switch really


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 Post subject: Re: KT120 Oddblocks
PostPosted: 28 Jan 2018, 17:01 
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Joined: 04 Jun 2008, 20:59
Posts: 3552
Location: Arizona, USA
Hi, Yes you can build them on a single chassis. Be aware that it will be very heavy and be sure to use a very strong chassis. The amp will be in the 70 pound (45kg) range.

Good listening
Bruce

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 Post subject: Re: KT120 Oddblocks
PostPosted: 28 Jan 2018, 17:41 
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Joined: 08 Aug 2009, 03:11
Posts: 2161
Location: Chilliwack, BC
I use an "L" bracket along the underside, mounted with the transformer screws. Provides strength and a convenient place to attach terminal strips, turret board, etc. :D

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