Elekit TU-879S 6L6GC

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first post...

Hi all,

Happy holidays! My first post here, but have been viewing the thread for a while and finally ordered a tu-879s. The amp is almost here and thought to ask for a consensus on what upgrades I should do straight away during the build? I haven't seen the full schematic yet, but wanted to see what I should order for caps upgrade as I assemble (manufacturer, uF values, and quantity).

Thanks in advance all!
 
Originally Posted by Cubdriver Aug 2012:
Bah!! Of course I join this forum and find this thread shortly AFTER ordering the kit from Tube Depot. I guess I'll have to see how it goes with the supplied power transformer and then go from there.

This has been an enlightening thread!

-Pat

Hi Pat

Yes, your TU-879S has an aftermarket R-core. If you are not happy about your aftermarket R-core. I have an original Japanese R-core in stock.

My wife purchased this kit for me from Tube Depot this Christmas. (I'm in Canada and sorry I wasn't able to do anything about this). On their site they say the supply the Japanese R-Core ... Is this still an after market transformer?

If so, do you have the original in stock? Is it on your website?

Thx
Dave
 
Is this still an after market transformer?

If so, do you have the original in stock? Is it on your website?

Thx
Dave[/QUOTE]

If you bought TU-879S recently from Tube Depot you should have original R-core.

For the past 8 years, hobbyists have been asking for certain features to modify the TU-879S kit. The highly regarded Elekit designer, Mr. Fujita, has taken all those specific features and specifications into consideration and we are happy to welcome the release of the newly designed TU-8200 in January 30, 2014. TU-8200 has a lot more improvements from its predecessor(TU-879S).




The picture is the latest TU-8200DX with 4 smaller organic caps and 4 Amtrans AMCO 104 Metalized PET film capacitors.
Mr Fujita recommends using organic cap in TU-8200. Although the cost is slightly higher, I want to offer this amp with the best possible parts within the budget.

TU-879S is a very good budget amp kit but TU-8200 is superior to TU-879S in all respects.
 
Is this still an after market transformer?

If so, do you have the original in stock? Is it on your website?

Thx
Dave

If you bought TU-879S recently from Tube Depot you should have original R-core.

For the past 8 years, hobbyists have been asking for certain features to modify the TU-879S kit. The highly regarded Elekit designer, Mr. Fujita, has taken all those specific features and specifications into consideration and we are happy to welcome the release of the newly designed TU-8200 in January 30, 2014. TU-8200 has a lot more improvements from its predecessor(TU-879S).


...

The picture is the latest TU-8200DX with 4 smaller organic caps and 4 Amtrans AMCO 104 Metalized PET film capacitors.
Mr Fujita recommends using organic cap in TU-8200. Although the cost is slightly higher, I want to offer this amp with the best possible parts within the budget.

TU-879S is a very good budget amp kit but TU-8200 is superior to TU-879S in all respects.[/QUOTE]


Thanks for the information Victor but as stated my wife has already purchased the 879S for me and it's on it's way. And this is fine. I've never built a kit before so the 879S is the perfect starter. I will learn from this experience and move on to a dream build some time in the future after I have gained experience modding this kit out and having fun with it.

Thanks for providing the forum and all the wonderful feedback.
 
Thanks for the information Victor but as stated my wife has already purchased the 879S for me and it's on it's way. And this is fine. I've never built a kit before so the 879S is the perfect starter. I will learn from this experience and move on to a dream build some time in the future after I have gained experience modding this kit out and having fun with it.

Thanks for providing the forum and all the wonderful feedback.
[/QUOTE]

If you follow the manual step by step, you should be ok. If you have any questions, please let me know. I will do my best to assist you. DIY is my passion
 
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I upgraded to the 0.1muF vitamin-Q caps yesterday at C1,C2 and C5,C6. Initial impressions are good. The bass lines now have a life of their own ( which was earlier missing this definition with the new PIO caps - even with a REL T5 sub with speaker level inputs). Also new is a hint of drama that lends to emotion in the musical presentation which was completely absent earlier. In fact my $60 Sony DSX-A30 FM HU with a DSP provided a sense of drama that the 879S lacked all these days. Not any more, although it may not be the greatest at conveying it, at least it has arrived on the scene! The music also gels together much better with these caps that cost me just $$ (less than 20). Funny to think that I spend $$$$ for a DAC precisely for the sense of cohesion (was a major justification in my mind at least) and it was still lacking somehow. I guess one $$$$ component is not going to make up for the weakness of the rest of the chain. At last now they seem to be bringing out the good (if not the best) in each other in a complementary fashion.

The sound is a little compressed overall and thick in the lower mids right now though - appeared to open up the top end a bit after 10 -12 hours of burn-in which is consistent with my experience of all solid state components I have owned so far. Hoping to hear further improvements after 25 to 40 hours...

Now it is time to think of improving the sound with tube rolling and get rid of the 6L6s I own for some $$. I have the EH 6L6GC and while the top and bottom end is really great, it is of a sticky congealed type (like walking on freshly laid tar). The SED Winged =C= has a harmonic bloom to die for overall but is lacking the same top and bottom end punch of the EH. Between them the =C= wins as of now as I choose to sacrifice the punch for the harmonic fullness of the =C=.

A pair of Psvanne treasure mark II 12ax7s are on the way lying in a customs warehouse awaiting clearance (right now I use a Jan-Philips 5751). Now I think I will go for either a KT-66 (either Gold Lion reissue or JJ) or the much cheaper RCA 807s. Cant make up my mind which.

The JJ is supposedly tolerant of lower voltages. I don't know how the GL will sound if the 879S does not supply the optimal voltage a KT-66 needs (to sound its best) during typical operations? I suppose the tranny in this kit is designed and tested to be able to supply the required 1.3amps over the 900ma of the 6L6 which is why the KT-66 is an option. How much voltage does the KT-66 need to sound its best? I guess I need to re-read on self-biasing or auto-biasing and understand it better. What are the limits for variance in this amp circuit? Typically within 20% I hear? Will it run the KT-66s at 60% or 70% or 75%? I don't know. (since a tubes performance varies in a particular circuit with its supplied voltages, that makes me wonder).

What I am looking for is really taut and deep and articulate bass with punch with a good forward splash of cymbals (currently too recessed due to my speakers) and the fullness of the =C= retained in mid balance. The GL reviews tempt me with words like articulate, touch response (quick footed) and dynamics (should translate to more life in musical presentation). The JJ reviews tempt me with deep tight bass and the british rock sound. Maybe if somebody who has both can assure me the GL packs a similar punch in the lows, I guess will go for it instead.

And then I still want to hear the vintage NOS sound of the original RCA 807 that is supposed to have a good balance all through the spectrum and supposedly beats all new production tubes.

Which ones do you guys recommend?

Thanks
--G0bble
 
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I had been considering upgrading my caps. I had this done to my Virtue M-901. But I think I'll stick with rolling tubes - try some KT-88s and the like. I don't believe my ear is good enough to tell the difference in changing parts like caps (and then there's articles like this: Atlantic Quality Design, Inc., The Truth about Tone Capacitors ). The 879S is after all a fairly low end amp in the grand scheme of things and I purchased it as a learning experience and a gateway to better things later. (ie ANK Audiokits - Interstage C-Core MonoBlock 300B Tube Amplifier)
 
I had been considering upgrading my caps. I had this done to my Virtue M-901. But I think I'll stick with rolling tubes - try some KT-88s and the like. I don't believe my ear is good enough to tell the difference in changing parts like caps (and then there's articles like this: Atlantic Quality Design, Inc., The Truth about Tone Capacitors ). The 879S is after all a fairly low end amp in the grand scheme of things and I purchased it as a learning experience and a gateway to better things later.

Well my humble suggestion to you is that if you cannot discern the difference after changing caps you should seriously not bother with "high end" audiophile gear and stick to the "low end" amps and save yourself some serious money. Maybe donate it to charity.

I think the KT-66 requires 250V under normal operating conditions in class A and not the 400+V as I imagined. So it should be ok with a KT-66 after all (like was originally claimed :spin: ). I'll settle for the GL KT-66 I guess :)

--G0bble
 
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Didn't read the link?

Cheers
Dave

Hey no grudge. I did read the links. But then I do believe I hear differences with different caps, different cables even for digital spdif and usb and I hear differences when I bump and lower the realtime priority of the music player process on a low latency linux kernel. So for me I can justify spending when I decide to afford something.

But honestly, if you can't and don't believe, then why spend $$$$ on an amp with expensive components when your ears (or mind) won't tell the difference?

This argument cannot be won by either side. Go by ones own conviction - its our hard earned money after all. :spin:

Cheers
--G0bble
 
Hi everyone,

I would like to experiment with some different caps in the power supply of my TU-879S. Can anyone tell me the number of the capacitor I need to replace? (C15, C17, etc)
Also, what is the minimum voltage handling for that cap?

Thanks

Check this:
The stock electrolytic power supply caps have been disconnected, and replaced with a Mundorf Mylitic capacitor. This cap is huge, and needed to be relocated under the transformer cover, but makes a significant addition to the sound.

Elekit TU-879S Japanese Kit Single Ended Pentode Integrated Tube Amplifier

Edit: oops it does not mention which, but the manual should tell you which ones and their ratings … What do you plan to replace them with?

--G0bble
 
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Gobble, thanks but I've already seen the quote about the Mundorf Mylicit cap. The problem is I have looked at the manual and I'm still not sure which cap or caps I need to replace. The two largest ones are 100uF electrolytics, but I'm not sure if I should be replacing both of them or just one of them. They both look like they are more or less in the power supply section.

The ratings for the stock electrolytics are 400V, but if I could go lower it would give me some flexibility and some cost savings in the caps I'm trying out. I'm planning to try the ASC X386S caps. They're huge, so I'll need to sit them at the side of the amp and attach them with wires. Not convenient, but I would really like to hear what a top notch power supply cap can do for the sound.
 
Gobble, thanks but I've already seen the quote about the Mundorf Mylicit cap. The problem is I have looked at the manual and I'm still not sure which cap or caps I need to replace. The two largest ones are 100uF electrolytics, but I'm not sure if I should be replacing both of them or just one of them. They both look like they are more or less in the power supply section.

The ratings for the stock electrolytics are 400V, but if I could go lower it would give me some flexibility and some cost savings in the caps I'm trying out. I'm planning to try the ASC X386S caps. They're huge, so I'll need to sit them at the side of the amp and attach them with wires. Not convenient, but I would really like to hear what a top notch power supply cap can do for the sound.

A lot of tubes operate operate in the 400-500V dc range. I suppose the PSU needs that much in the ac range to be stable and safe. The amp may malfunction if you swap a tube that draws a lot of power. Electrical Safety is an issue one cant overlook either.

Sent from my GT-N7000 using Tapatalk
 
Volume Potentiometer

If you follow the manual step by step, you should be ok. If you have any questions, please let me know. I will do my best to assist you. DIY is my passion[/QUOTE]

Of all the things I'd like to change to begin with, the volume potentiometer looks like one of the more difficult pieces to change later. Could I get a few good recommendations? I'm quite the amateur and couldn't tell a 10K unto from something else.... Or even if that's what I would be looking for. The ones I see online appear quite a bit bigger than the one that came with the kit. Like the ALPS-68580 controls_pot_alps

Thx
Dave
 
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