Thanks. That is what I figured but it's nice to have confirmation.
Still early hours but first listen with the TU-8900 running WE 300Bs and the Z1R headphones is very positive.
Steve Z
Still early hours but first listen with the TU-8900 running WE 300Bs and the Z1R headphones is very positive.
Steve Z
I don't know about the TU-8900, but with my TU-8200R I had to be careful with how much power I tried to run through the headphone output resistors.
I appreciate your caution. However, I'm not burning in the amp -- I've had it for some time. If I were needing to get hours on it, I'd just put it back in the main system and play lots of music.
Thanks,
Steve Z
Thanks,
Steve Z
I know it's early days, but after you've gotten used to the 300Bs you should try some 2A3s. I'm running Linlai Global Elite 2A3s and now it's the best sounding amp I've got.
Thanks for the kind suggestion. I wasn't very clear with what I've written. I've actually had the TU-8900 for some time, it's only early hours for the headphones. I've got several pair of 2A3s I've used with the Ele-kit, including the Cossor/LinLai Victor sells as well as some very early blackplate RCAs.
I agree with you (almost) completely -- lovely sound and I'm very happy with it. My Sunvalley SV-S1645D running NOS 46/VT-63 via socket adapters however still takes pride of place in my main stereo system.
But both are wonderful. It is good to have choices!
Best regards,
Steve Z
I agree with you (almost) completely -- lovely sound and I'm very happy with it. My Sunvalley SV-S1645D running NOS 46/VT-63 via socket adapters however still takes pride of place in my main stereo system.
But both are wonderful. It is good to have choices!
Best regards,
Steve Z
I built my 8900 back in late 2021. Things happens and I haven't had much time with it and only recently able to spend more time with it. The transparency and airiness, and liquidity and spaciousness is quite addictive. Now it is not a very powerful amp but with the right speakers can really provide some full range music of moderate scale. While not gonna be earth shattering but I am driving a 94dB-ish speaker (diy, with JBL 4367/M2 components), it surprising hold its own with decent dynamic in the lower registers. Job well done Victor and Fujita-san.
Specs on mine are:
After 3 years, what are the recommended upgrades these days?
Specs on mine are:
- Amorphous OPT
- Mullard cv4004
- Cossor WE300B
- Duelund CAST-PIO Cu/Sn 0.1uF
- stock resistors/caps
After 3 years, what are the recommended upgrades these days?
You could ditch the stock potentiometer and use an external Autoformer Volume Control, which brings about a nice improvement, although this would be an expensive route. Supposedly, the Alps RK50 (again expensive and also huge) is a nice improvement over the affordable pots.
Some of the cost effective mods are;
- You could replace the stock resistors with better resistors. Even the Amtrans AMRG was an upgrade
You could replace the jumper resistors with good copper or good silver wires
- Bypassing the power supply caps C112 and C212 with film caps also resulted in a slight improvement
Do the following mod at your own risk:
On the affordable side, the biggest improvement for me and my friends came about, when we replaced those cathode bypass caps. The stock ones are polymer aluminum caps from Kemet. We replaced those with electrolytics. I went with Nichicon ES in all positions. Whereas, my friend went with a mix of ES and KZ, which is probably what I’d do if I had to do it again. The only issue with this mod is, these caps are quite a bit larger than the stock caps. So these have to be mounted on the underside of the PCB and they cover up most of the PCB. So if you want to do any mods or soldering in the future, it becomes almost impossible, unless you remove those caps and reinstall them.
A more safer route would be to replace those Kemets with Panasonic OS-CONs, which are still polymer anluminum and low ESR caps, just like the stock Kemets. However, these Panasonic OS-CONs have a reputation for sounding good among the polymer aluminum category, so might be worth checking out.
This is what it looks like. The orientation of the caps are not random. Due to space constraints and lead lengths, I had to simulate and I arrived at this. In the pic, you can also see the power supply cap bypassed with a film cap.
Some of the cost effective mods are;
- You could replace the stock resistors with better resistors. Even the Amtrans AMRG was an upgrade
You could replace the jumper resistors with good copper or good silver wires
- Bypassing the power supply caps C112 and C212 with film caps also resulted in a slight improvement
Do the following mod at your own risk:
On the affordable side, the biggest improvement for me and my friends came about, when we replaced those cathode bypass caps. The stock ones are polymer aluminum caps from Kemet. We replaced those with electrolytics. I went with Nichicon ES in all positions. Whereas, my friend went with a mix of ES and KZ, which is probably what I’d do if I had to do it again. The only issue with this mod is, these caps are quite a bit larger than the stock caps. So these have to be mounted on the underside of the PCB and they cover up most of the PCB. So if you want to do any mods or soldering in the future, it becomes almost impossible, unless you remove those caps and reinstall them.
A more safer route would be to replace those Kemets with Panasonic OS-CONs, which are still polymer anluminum and low ESR caps, just like the stock Kemets. However, these Panasonic OS-CONs have a reputation for sounding good among the polymer aluminum category, so might be worth checking out.
This is what it looks like. The orientation of the caps are not random. Due to space constraints and lead lengths, I had to simulate and I arrived at this. In the pic, you can also see the power supply cap bypassed with a film cap.
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Some ambitious mods -- very nice.
I'd love to have a high-performing remote volume control on my TU-8900, though I have to say that currently the Ele-kit is very close to my chair since it's been doing admirable headphone duty with a pair of Sony MDR-Z1R 'phones. However, if and when it goes back into the main system a remote volume control would be very nice.
A totally non-invasive modification is to buy a pair of Western Electric 300Bs from Victor. I've gone back and forth with 2A3s and the Western Electric 300Bs, including some really nice NOS black-plate RCA 2A3s, a Mullard 2A3 and the Cossor WE2A3 (my favorite 2A3 in the Ele-kit, go figure). But for my ears, system and musical tastes the Western Electric 300B is the current champ. I have not tried any of the other premium 300Bs such as Elrog, Emission Labs or Takatsuki however.
Steve Z
I'd love to have a high-performing remote volume control on my TU-8900, though I have to say that currently the Ele-kit is very close to my chair since it's been doing admirable headphone duty with a pair of Sony MDR-Z1R 'phones. However, if and when it goes back into the main system a remote volume control would be very nice.
A totally non-invasive modification is to buy a pair of Western Electric 300Bs from Victor. I've gone back and forth with 2A3s and the Western Electric 300Bs, including some really nice NOS black-plate RCA 2A3s, a Mullard 2A3 and the Cossor WE2A3 (my favorite 2A3 in the Ele-kit, go figure). But for my ears, system and musical tastes the Western Electric 300B is the current champ. I have not tried any of the other premium 300Bs such as Elrog, Emission Labs or Takatsuki however.
Steve Z
I've tried both output tubes and I prefer the 2A3s. I'm currently running Linlai Global Elite and the TU-8900 is the best sounding amp I have. I've also got a TU-8850 and a TU-8600S.
I have to agree as well although I haven’t tried any real good 300B’s in my system yet. RCA black plate 2A3’s are sublime however and really engaging. Those combined with rca clear tops give a very transparent and almost psychedelic experience.
Hi Victor, just wanted to thank you again for all the help you provided about 1.5 years ago. This is not just the best sounding system I’ve had, but it was SO much fun to build as well, with your guidance on hand to help as needed. Just wanted to send a note of appreciation for bringing these systems in and making sure we all get to the place we’re supposed to.
-K..n
-K..n
I am wondering what’s wrong with Kemet polymer caps? They are long lasting and very low ESR and I have been using them in other projects as well with very good result. Its small size makes it easy to use.
I don't think there is anything wrong with the polymer caps. They are very reliable and long lasting. That said I think it would be an interesting experiment to swap out those caps but ultimately (me personally) I'd probably just prefer to save my money/ time and buy more and different coupling caps. I've been running some cheap Amtrans caps since I built mine and will be upgrading to Jupiter copper caps this week hopefully.
Now I hopefully have done allmost all soldering. Waiting for the upgraded TDK pot and trying to decide if I should upgrade CuTF to V-cap or Audio Note Silver. Both where recommended by Victor (and boy what a super quick reply!) Is there anyone who have tried both and what is the difference? I might wait and save up some money for the AN if there is a significant improvement vs V-vap. Anyway Inprepared by soldering the original high enough to easily be cut away. Thanks for that idea forum member!
Victor: what’s your thoughts about this? I thought I might ask here instead of by mail since I expect interest from several builders.
Br
Peter
Victor: what’s your thoughts about this? I thought I might ask here instead of by mail since I expect interest from several builders.
Br
Peter
Both coupling caps are excellent choice.
It is more about your budget. Stereophile classified TU-8900 as Class A components is based on AN silver caps and Tantalum resistors in signal path upgrade.
I offer ALPS R27 volume pot as the standard of TU-8900. I stopped to use TKD in TU-8900.
It is more about your budget. Stereophile classified TU-8900 as Class A components is based on AN silver caps and Tantalum resistors in signal path upgrade.
I offer ALPS R27 volume pot as the standard of TU-8900. I stopped to use TKD in TU-8900.
Really? Would you recommend the original one or will the TDK still be better?
I haven’t looked carefully on how the chassis is mounted - so my question: is it a hazel to do upgrades with tantalum resistors later? Maybe I should make sure it works before investing more money into it?
I haven’t looked carefully on how the chassis is mounted - so my question: is it a hazel to do upgrades with tantalum resistors later? Maybe I should make sure it works before investing more money into it?
Nobody tried those?
I’m really happy with the Cossor 2a3 but I’m thinking about selling the Cossor 300B to get the EmissionLab 2a3. Even if the 300b looks so so nice 😆. I really prefer the 2a3!