These are the upgrade parts for Premium Version
- Lundahl LL2777B Output transformer + PCB to config the wiring + HV cables + TU-8400 $1,175.00
- Audio Note Copper 0.1 X 2 $65 x 2
- ALPS R27 Volume pot + Metal Knob $40
- ECC83/12AX7 X 1 + KT170 x 2
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This amp looks very interesting! If I'm understanding the review correctly it is designed to be used as with a preamp as the gain from the RCA input is quite low. If you use the input on the front the gain is increased due to the opamp. Did I get that right?
yes,, the op-amp will increase the gain. you can do op-amp rolling too. . if you want the best sound. it is good to use with preamp.
Possible with TDK 2CP-601 as pictured rather than RK27?
Assume 5 jumper wires are needed.
Assume 5 jumper wires are needed.
Dear Victor, all, so what are the differences between the TU-8400 and the TU-8200R?
One difference I see is that it comes with KT-170 tubes, which need a higher cathode heater current (I just learned that in another thread). So the primary transformer and heater supply circuit must be different.
The output transformers are the same Lundahl LL2777 B with 70mA current spec as in the TU-8200R. So, were the LL2777 B transformers not quite fully used in the TU-8200R, and the TU-8400 is pushing them a bit more?
Or is it just things like for example output impedance that are different (maybe lower?), and drive the speakers differently? I actually don't know what the KT170 output impedance (slope of anode voltage vs anode current at the operating point) is compared to say the KT88 and the 6L6GC. Does anybody have a table of that?
One difference I see is that it comes with KT-170 tubes, which need a higher cathode heater current (I just learned that in another thread). So the primary transformer and heater supply circuit must be different.
The output transformers are the same Lundahl LL2777 B with 70mA current spec as in the TU-8200R. So, were the LL2777 B transformers not quite fully used in the TU-8200R, and the TU-8400 is pushing them a bit more?
Or is it just things like for example output impedance that are different (maybe lower?), and drive the speakers differently? I actually don't know what the KT170 output impedance (slope of anode voltage vs anode current at the operating point) is compared to say the KT88 and the 6L6GC. Does anybody have a table of that?
TU-8400 can use KT170 and only 2 coupling caps
LL2777B can work in TU-8200R and TU-8400.
When there is new amp from ELEKIT, I want to make sure it can run KT170 tube. It is the same for Sun Valley AMPs.
LL2777B can work in TU-8200R and TU-8400.
When there is new amp from ELEKIT, I want to make sure it can run KT170 tube. It is the same for Sun Valley AMPs.
Hi Victor! The main transformer of 8400 is useable with the 8200R? (as I understand the 8400 has a bit more potent R-core transformer as the 8200R)
There is no doubt.. TU-8400 is another wonderful design from Mr Fjita
Please make sure to pick the right Power Board 100V/115V/230V
Installation of ALPS R27
You need to cut the volume pot pcb from unit 2 and solder with a thin wire ( pt1 to 5)
Connect all 5 wires to unit 2
You can replace the OP-AMP to fit your taste (only for input-2, input-1 does not go through the OP-AMP)
With upgrade - Audio Note Copper 0.1 coupling cap
Please make sure to pick the right Power Board 100V/115V/230V
Installation of ALPS R27
You need to cut the volume pot pcb from unit 2 and solder with a thin wire ( pt1 to 5)
Connect all 5 wires to unit 2
You can replace the OP-AMP to fit your taste (only for input-2, input-1 does not go through the OP-AMP)
With upgrade - Audio Note Copper 0.1 coupling cap
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After 1 hour listening,,, this is a prefect amp for you to enjoy music.
My motto "WE offer Good and Affordable DIY kits" I want to say AFFORABLE...
For less than $1K, you can own this wonderful creation from Mr Fujita. ELEKIT is 100% made in Japan
The music from TU-8400 is very nice but what I enjoy more is the building process.
You can use EL34/6L6/KT77 ~KT170 to fit your taste...
My motto "WE offer Good and Affordable DIY kits" I want to say AFFORABLE...
For less than $1K, you can own this wonderful creation from Mr Fujita. ELEKIT is 100% made in Japan
The music from TU-8400 is very nice but what I enjoy more is the building process.
You can use EL34/6L6/KT77 ~KT170 to fit your taste...
This 47 Labs CD Player was designed by Mr Kazutoshi Tsukahara (Now is Sparkler Audio in BEPPU Japan.
I made it in 2013 as a kit. I love to use this CD player to test new amp.
I made it in 2013 as a kit. I love to use this CD player to test new amp.