Building the TU-8900

My new TU 8900

Thanks for the tube suggestion. This is my first Elekit so i have mothing to compare like you guys. My existing 300b tube amp is based on Chinese made antique sound lab which has served me well in the last 21 years. But this TU-8900 is way above that both in term of build and component quality and sound. I upgraded some of more critical components from stock. I spent last evening playing many of my old CDs, very musical. Spent short time listening to my HD660 with this amp, generally good impression but too soon to comment on how it compares to my Asgard 3. So far my experience on 300B are only on EH gold pin. I had Gold Lion and Full Music but i no longer have them to compare. I am running it now as integrated but will try with preamp next week. I also played around with NFB. Reading many of your great comments made me want to try 2A3 which i had not even listened once. I am still debating if worth getting RCA grey plates if NOS/low used. somehow i like RCA products from my super good experience on RCA 6072. Will try to share some picture.
 
My TU 8900 pictures

A couple of pictures to share. Not finished but already singing
 

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I haven't received the Crossors from Victor yet, just playing with some Sovtek 2A3's and EH 12AU7's, this amp sings! The resolution and dynamics are scary good. Bass is a bit soft and wobbly to me, will burn in the tubes and try others. Very dynamic amp and tubes!

Let us know the differences you hear. I have not heard Sovteks but from my research some like it but most are not too favorable,but I don’t judge and at the end of the day it is your taste. Use the existing tubes to burn in your 8900. I don’t know what caps you are using but that could also take time. Vcaps can take over 100 hours according to posts on the web. To be honest I never heard a difference in my Sun Valley phono preamps vcaps and I have over 300 hours but I lost track of usage.
 
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When running 300B, the board gets too hot to touch. Not burning but beyond comfortable level. Same as 270 ohm/5W resistors. Hope it helps.

Hi mchandra, Thank you very much for your information.

I am now very scare for something when it getting hot. Last year, I got my Class A F5 amplifier burnt and damaged to one of my Coral Beta 8 full range speaker in the Summer time. Since that, I bought another pair F5, and added a speakers protection for safety reason.
 
I am not too sure the main reason caused to it to burnt.

The F5 is the kit I bought from DIYaudio store, but they run out the JFET. So, I bought the JFET from one Ebay seller in Hong Kong. Could be they are fake. In F5 the pair of JFET running very hot, even I can not left my finger on them in a long time. I don't like this way.
 
I am not too sure the main reason caused to it to burnt.

The F5 is the kit I bought from DIYaudio store, but they run out the JFET. So, I bought the JFET from one Ebay seller in Hong Kong. Could be they are fake. In F5 the pair of JFET running very hot, even I can not left my finger on them in a long time. I don't like this way.
Any part (JEFET, Transistors, etc) you buy from eBay this is shipping from China is FAKE. These are confirmed reliable companies that sell NOS Real parts.
B+D Enterprises - Home page
LittleDiode – Electronic Components for All
 
Thanks Neville and CohibaJoe for the inputs.

I just got another information from the Elekit distributor in Australia. They told me the temperature that they measured for me was read 46.7oC at the room temp.

Now I am on thinking, if I buy this kit, should I need to add heat sink or small fan on top of the two red boards or not?
 
If your reference voltages are within range , your amp should be working properly.
The PCB board should be warn not HOT..
Mr Fujita's design is no heat sink. If your pcb is hot or over heat , your reference volages should be out of range. Your LED will turn to RED ie over current...

The manual does not ask you to measure the temperture or add a hear sink.. but the manual wants you to check each test point.
 
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Always a good day when a box or two arrive!

Thanks Victor and DHL for a speedy delivery, three days international delivery is pretty impressive in my book.

Made a start of sorts already as have soldered the Vcaps into my Bottlehead Sex amp as bypasses on the output caps to get some hours on them prior to installing them into my 8900.

I'm looking forward to getting started on the actual build next week.
 

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