The relevant impedance is the large grid resistor to ground (or to a negative bias supply).
The small series grid resistor (between the capacitor and grid) is not a factor.
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Rayma I see what you mean now. You are right I believe. I am still pretty new to the design aspects of this stuff. I get confused and I miss things. I would call that resistor the grid leak resistor? And it is definitely higher resistance than the plate resistance. Again probably doesn’t matter all that much, but I’m trying to learn things by building these kits.
Amazing service from Victor. Ordered Friday morning and received the shipment Monday afternoon. The family was out Tuesday so I spent the afternoon really enjoyed putting it together. The Elekit is put together so nicely. Not only does the circuit sound good, so much thought is behind every detail. All parts are supplied in their exact quantity. The resistors are somewhat sorted in small baggies. So luxurious to have 0R jumper resistors instead of just a piece of disposed wire. All physical dimensions are tight. Headers with multi legs have zigzag offset holes so they don't fall off when the PCB is flipped around. Multiple PCBs are assembled into one unit to be installed onto the base chassis and the front panel fits in with perfect precision into the whole unit. It is like a well choreographed ballet.
The kit is not cheap by any means, but it is a great value for such high quality. I have put together kit from a even "higher end" kit maker, and Elekit really put them to shame in all dimensions.
First time turned on there was no sound, no light, nothing. turned out i missed the fuse holder. Luckily it was on the power board so I didn't need to disassemble the whole thing. Once that was fixed, the amp just worked. Test points came out within specs, but there are some slight difference between the channels within the margins. I will re-visit it after a bit of burning in.
Currently burning in with Mullard CV4003 and new pair of Linlai/Cossor WE300B. Sounding pretty good already. I played around with CuTF and Mundorf SGO. Both have their own sound but too early in the burn in to make any judgement.
Even so, I have been sitting here enjoying music all evening, nice and relax after spending 6 hours putting it together.
The kit is not cheap by any means, but it is a great value for such high quality. I have put together kit from a even "higher end" kit maker, and Elekit really put them to shame in all dimensions.
First time turned on there was no sound, no light, nothing. turned out i missed the fuse holder. Luckily it was on the power board so I didn't need to disassemble the whole thing. Once that was fixed, the amp just worked. Test points came out within specs, but there are some slight difference between the channels within the margins. I will re-visit it after a bit of burning in.
Currently burning in with Mullard CV4003 and new pair of Linlai/Cossor WE300B. Sounding pretty good already. I played around with CuTF and Mundorf SGO. Both have their own sound but too early in the burn in to make any judgement.
Even so, I have been sitting here enjoying music all evening, nice and relax after spending 6 hours putting it together.
Victor I also want to express my gratitude and many thanks for
your dedication to these kits. I just finished my TU-8900 last night
and it’s running perfectly with all voltages in check. Already
sounding wonderful with less than 2 hours use. I’m using the
Cossor WE2A3 and the Sylvania 12BH7. I was thinking that 3.5
watts might not be enough power for me and my speakers, but I
was wrong. It’s plenty of power. And wow the openness,
transparency, and detail. I can’t imagine what it might sound
like after 100 hours. Again thank you Victor. I’m hooked.
your dedication to these kits. I just finished my TU-8900 last night
and it’s running perfectly with all voltages in check. Already
sounding wonderful with less than 2 hours use. I’m using the
Cossor WE2A3 and the Sylvania 12BH7. I was thinking that 3.5
watts might not be enough power for me and my speakers, but I
was wrong. It’s plenty of power. And wow the openness,
transparency, and detail. I can’t imagine what it might sound
like after 100 hours. Again thank you Victor. I’m hooked.
it is my pleasure to work with the DIY community..
The shipping cost is the too high
Fedex charges $210 to ship each amp out of Japan...The shipping cost does not include the Lundahl from Sweden and the amp+ lundahl from Vancouver via DHL to yoy..
Bascally I only charge 1/3 of the actual shipping $345.
The shipping cost is the too high
Fedex charges $210 to ship each amp out of Japan...The shipping cost does not include the Lundahl from Sweden and the amp+ lundahl from Vancouver via DHL to yoy..
Bascally I only charge 1/3 of the actual shipping $345.
Victor is totally awesome to deal with. We as a community are lucky to have Victor. Today I swapped out my Jensen transformers to Lundahl 1690 as an input pair for balanced input. There are upgraded performances from VS the Jensen. Soundstage is wider VS Jensen which is narrower, the depth is a bit elusive as I think the Jensen is narrower so it projected about similar depth but the illusion is deeper. Also the Lundahl has better retrievals in low and high extensions, clarity and airiness is also upped a bit. It is definitely worthy an upgrade
Thank you Victor once more, it isn’t your cup of teas to special order the 1690 but you did so for me anyways!!! Love it !
Thank you Victor once more, it isn’t your cup of teas to special order the 1690 but you did so for me anyways!!! Love it !
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Well what's to say, my TU-8900 seems to be sounding better than ever I'm long past the point where I was listening intently to the amp and am now just enjoying playing music.
After spending a week enjoying listening with the 300b with no negative feed back I decided to swap the 300b's out and revisit running 2A3 with no feedback. This combination I've tried several times before and it's a combo that to be honest has never really gelled for me.
Surprise surprise I've been revelling in the sonic landscape its been painting for the last week. Every now and then as I play through familiar tracks it serves up a soundscape that makes me pause in what ever I'm doing whilst I savour in equal measures of amazement and disbelief at the deliciousness of the moment.
After spending a week enjoying listening with the 300b with no negative feed back I decided to swap the 300b's out and revisit running 2A3 with no feedback. This combination I've tried several times before and it's a combo that to be honest has never really gelled for me.
Surprise surprise I've been revelling in the sonic landscape its been painting for the last week. Every now and then as I play through familiar tracks it serves up a soundscape that makes me pause in what ever I'm doing whilst I savour in equal measures of amazement and disbelief at the deliciousness of the moment.
Hi what do you think about kemet cathode bypass cap 330u/35v that came with the kit? From the specs, it seems good quality but i think like others, I am wondering if i can improve it. Would love to hear from anyone who have tried to change and maybe Victor’s opinion. I just cannot stop my upgrading bug.
Thanks.
Thanks.
You need to know why Mr Fujita uses this type of low ESR cap. You need low ESR cap in that location. Sometime expensive parts will give you opposite result. ie high ESR.. We need low ESR.
I only recommend to change the coupling cap. I recommend to look at Audio Note 0.1 Silver Cap...
I only recommend to change the coupling cap. I recommend to look at Audio Note 0.1 Silver Cap...
Hifihuner,
I'm contemplating purchasing and building this amp in sometime in the future, as I just purchased a 8600S kit not too long ago and will work on that first.
Without having the instructions and parts list for the 8900, I am at a loss to as to what value resistors to purchase.
Would you be able to share the resistor list with us here, or PM me with the list of necessary resistors? I am also interested in ordering the Takman as an upgrade.
Thank You!
I'm contemplating purchasing and building this amp in sometime in the future, as I just purchased a 8600S kit not too long ago and will work on that first.
Without having the instructions and parts list for the 8900, I am at a loss to as to what value resistors to purchase.
Would you be able to share the resistor list with us here, or PM me with the list of necessary resistors? I am also interested in ordering the Takman as an upgrade.
Thank You!
KT here is the list of resistors for 8900. Like Victor says the resistors in this kit are better than those in the 8600. Personally I like to match resistors very closely and I wanted extras so I bought Takman and Kiwame for 5 watt.
Victor I hope this list is ok to post. If not please delete.
Victor I hope this list is ok to post. If not please delete.
Thank You for sharing....Their are price points to meet to the quailty of the components used. I had replaced Resistors, Caps, Wiring and Jacks for Sunvalley SV-Pre1616D, SV-EQ1616D and I'm Very Happy what I hear. I would replace the KOA with Takman or PRP or Amtrans AMRT. We look forward to this build.