[mourip]

Anyone tried modifying the TU-8200 yet? Looks ripe for simple cap and resistor upgrades.

 

[JK-47]

  Anyone tried modifying the TU-8200 yet? Looks ripe for simple cap and resistor upgrades.

The TU-8200DX from Victor @VKmusic comes with upgraded resistors and caps already. Victor also offers a few other cap upgrades, and a few people in this thread (I know it's long) have tried other caps. Victor is also currently testing a few different transformers as well.
 
@Victor, how is the transformer testing going? Are you going to offer them for sale yet?

 

[430011]

I know I've seen photos of one with all the resistors replaced by AMTRANS AMRG. But at $4 a piece that is a mod I'm not prepared to undertake. It may be worth replacing just the resistors used in series for the headphone output. If I built another I may consider using Vishay RN55/60.
 
There is a fair bit of room on the board for upgrading coupling caps. I used Audiocap Thetas. Mundorfs would be nice to try, but may be a tough fit. I have some Russian teflons too but they would require some creative thinking to fit. Some of the electrolytic caps can be replaced with nicer electrolytics.
 
VK teased us with larger output transformers, but I haven't found any other information on them. I find this quite tempting.
 
One of the guys a few pages back did some work to allow the amp to use 12BH7 tubes, but combined heater draw has to be considered.
 
I would like to put a nicer pot in the amp. Due to the power of the amp I have to keep my volume pretty low, but left/right balance seems ok with the kit pot.
 
But at the end of the day the amp in stock kit form is damn impressive. Rolling tubes may be enough modding for most people. While they may lack the cachet of NOS there are lots of new manufacture tubes to try out at fairly reasonable prices. With NOS you may be able to recoup some investment if you pass the tubes on.

 

[430011]

 
@Victor, how is the transformer testing going? Are you going to offer them for sale yet?

 
Looks like I'm not the only one feeling the tease! 

 

[mhamel]

  I know I've seen photos of one with all the resistors replaced by AMTRANS AMRG. But at $4 a piece that is a mod I'm not prepared to undertake. It may be worth replacing just the resistors used in series for the headphone output. If I built another I may consider using Vishay RN55/60.
 
There is a fair bit of room on the board for upgrading coupling caps. I used Audiocap Thetas. Mundorfs would be nice to try, but may be a tough fit. I have some Russian teflons too but they would require some creative thinking to fit. Some of the electrolytic caps can be replaced with nicer electrolytics.
 
VK teased us with larger output transformers, but I haven't found any other information on them. I find this quite tempting.
 
One of the guys a few pages back did some work to allow the amp to use 12BH7 tubes, but combined heater draw has to be considered.
 
I would like to put a nicer pot in the amp. Due to the power of the amp I have to keep my volume pretty low, but left/right balance seems ok with the kit pot.
 
But at the end of the day the amp in stock kit form is damn impressive. Rolling tubes may be enough modding for most people. While they may lack the cachet of NOS there are lots of new manufacture tubes to try out at fairly reasonable prices. With NOS you may be able to recoup some investment if you pass the tubes on.

 
I'm the person that did the mods for 12BH7, but I also put a better pot in when I built the amp.  If you look at the board where the pot mounts, it can be clipped out, lowered/connected with jumpers and an Alps blue pot dropped in. I'm pulling the amp apart now to take a few photos.

 

[mhamel]

Here you go - Alps Blue installed.
 

 

 

 

[430011]

Wow that looks tidy! I think I have an Alps Blue or two floating around. Seems pretty straightforward. It might be time to break mine apart.

 

[430011]

By the way, what do you think of the 12BH7? I imagine you could even try a 6SN7 with an adapter, I believe they also draw 600mA.

 

[Effusion]

SuperDuke,

Thanks for letting us know about your experiences using speakers and I'm glad to hear the Elekit is pushing the HE6 well!  I think you've probably got the right idea about why the headphone out sounds better than through the speaker caps; either the resistors are different or the connections/connectors are losing some of the micro-detail, or even both to a degree.

As far as speakers, I actually haven't tried mine much with the unit, for various reasons, but I'm glad to hear your positive experiences!  Others have also commented on how well the TU-8200 does with efficient speakers and in near-field setups as well.  The versatility of the amplifier is in my opinion, other than great sq, it's biggest attraction.  So, the fact that it can probably run pretty much every headphone thrown at it, plus at the same time be able to drive efficient speakers extremely well, is impressive to say the least.

mhamel,

I really like your modded unit with the Alps Blue!  Do you happen to know what the resistance of the model you used is?

Evan99 and JK-47,

I third the notion that I'm interested in the potential OPT upgrades Victor is looking into as well.  I think that if they can get the size down and the specs right there would probably be some interest here and elsewhere, as the OPTs are always areas for potential degradation and the quality of them is everything regarding potential distortion.  I also haven't found much info on the beefer units by Atene, but the Lundahl units look really nice!!

 

[mhamel]

  mhamel,

I really like your modded unit with the Alps Blue!  Do you happen to know what the resistance of the model you used is?
 

 
Thanks!  Offhand, I don't recall, but it was the same resistance as the stock volume pot.

 

[430011]

I took the plunge and ordered an HD800. The price difference was just too wide for me to make the leap to the 800S. And if I'm keeping the 650 I feel like I can switch if a particular album is coming off too bright.

I've also been thinking of doing a little work under the hood. Probably will try some fancy resistors in the headphone section and I'm looking at pot upgrades. The break away section is nice for the blue velvet, but I may try a TKD if it would fit and just run fly leads. I need to do a little measuring.

 

[SuperDuke]

congrats on the HD800- I think you'll really enjoy them.

 

[430011]

With about 6 hours of listening time now I have to say I think the TU-8200 and HD800 will be a long term pairing for me. It is just fantastic. I have to say I don't really understand some of the characterizations of the HD800 I've seen online. I've seen people say it's like a pencil to the eardrum or that 1/3 of their music is unlistenable. I haven't heard a single "unlistenable" song through this. Yes, if a song is poorly recorded or mastered it is very apparent but that is much different. The real proof is that my fiancé gave a thumbs up after listening to a playlist I made her.

First aside: has anyone come across a compiled list of all the tubes that will roll in?

Second aside: over at diyaudio there is an Elekit sub forum and victor has posted a lot of good pictures, including more of the possible upgrade transformer. Still very intrigued by that.

 

[clams]

Quote:

  Here you go - Alps Blue installed.
 

 

 

What's the resistance of the pot? Was it a pretty easy install?

 

[mhamel]

  Quote:
What's the resistance of the pot? Was it a pretty easy install?

 
Offhand, I don't remember - I used the same value as the stock pot.
 
You have to clip out the section of the board that houses the pot... I did that, then sanded down the edges, made jumpers out of some of the heavier capacitor leads from the upgraded caps I installed. It already has pads sized for the Blue Velvet pot, so that part is simple. It's been a while since I installed it, but iirc, I mounted it to the small board, mounted the jumpers to that, fit it to get the correct height, adjusted the jumpers and soldered them to the main board.