[Whitigir]

If you want to have balanced input you'd need a pair of small transformers. Cinemag and Jensen both make them. I believe you also need to integrate a pair of resistors; you can check with them about the value.

I am planning with Lundahl dual transformers now LL1690. It doesn’t seem that it needs any resistors. The line in should be already with some kind of gains as the 8900 has the preamp tubes. So the transformers go right up to the input stages of RCA is alright. It is better than just going straight Balanced to SE

However, I need to see the schematic to judge further. Jensen recommend 2.4K resistors for between the output of RCA. Lundahl recommend a couple resistors and a cap

 

[Whitigir]

Operation checks and voltage check point readings passed.

No troubleshooting required.

It's alive....

Are you using the C cores ? Or the AM cores ?

 

[JamieMcC]

I went for the Lundahl amorphous core version with V-Cap CuTF capacitors and TDK indented pot options.

 

[Whitigir]

I went for the Lundahl amorphous core version with V-Cap CuTF capacitors and TDK indented pot options.

Very nice build!! And expensive too !!! Lol ? Any chance to try EAT 300B tubes ?

 

[JamieMcC]

Thanks I'm very pleased with the results and it's early days so far. Currently running the COSSOR/Linlai WE300B. I was originally going to go for the Cossor Black plates but was encouraged to go for the WE300B by an experienced 300B guy whom I've know for over ten years and who's advice I have high regard for.

Also purchased the COSSOR/LINLAI WE2A3 from Victor but have yet to try them.
No plans for trying other 300B's at the moment.

 

[HiGHFLYiN9]

Does the Linlai WE300B have any sort of guarantee? My brain has trouble wrapping around eight hundo for a pair of tubes

 

[Whitigir]

Does the Linlai WE300B have any sort of guarantee? My brain has trouble wrapping around eight hundo for a pair of tubes

Check out that ETB 300B . It is about double that much lol!!

I don’t know about those tubes but I will build this for HD800S prioritized, so 2A3 seems to be a good option

 

[JamieMcC]

The Cossor WE300B were $535 a pair not inexpensive but still significantly less than the USA WE300B reissue. Both plate structures are said to be identical.

I think the warranty for the Cossor WE300B is for 90 days.

 

[Whitigir]

The Cossor WE300B were $535 a pair not inexpensive but still significantly less than the USA WE300B reissue. Both plate structures are said to be identical.

I think the warranty for the Cossor WE300B is for 90 days.

Have you tried to compare 300B / 2A3 yet ?

 

[JamieMcC]

Have you tried to compare 300B / 2A3 yet ?

To early yet to make comparison on fresh amps they really need a couple of hundred hours on both tube sets before making any meaningful comparisons. fwiw TU8900 with Cossor WE300B is opening up nicely currently at 50hrs, definitely preferable sonics (to me) compared to fresh 2A3.
However that observation may well be reversed when I have 50hrs on the 2A3 will have to wait to find out...

Worth repeating its way to early to draw any meaningful conclusions on sonics without at least 200hrs plus of run time on the amp and both tube sets, roll a few different input tubes, try different settings etc.

But fwiw Im enjoying how it sounds.

 

[Whitigir]

I have tried different things on the kit. I only successfully implemented balanced 4.4mm as it is the connector I use the most. Could easily do XLR but not necessary. I failed to implement transformers differentials from XLR sources into the single ended rca in the back though

 

[Whitigir]

The amp sound much better when warmed up after 30 minutes or so, the details and high extensions just come out much better. I will upload a detailed build PDF later

 

[normie610]

The amp sound much better when warmed up after 30 minutes or so, the details and high extensions just come out much better. I will upload a detailed build PDF later

seems like you’re going back to desktop setup?

 

[HiGHFLYiN9]

I have tried different things on the kit. I only successfully implemented balanced 4.4mm as it is the connector I use the most. Could easily do XLR but not necessary. I failed to implement transformers differentials from XLR sources into the single ended rca in the back though

So you received the Elekit as well? You may want to post your quandary over at DIYAudio.com.

 

[Whitigir]

As promised, I have prepared al the documents for my build including “how to” modifications to run additional headphones or floating balanced and balanced transformers input.

you can download it here as a PDF . It is 1Gb! Enjoy !!