Is the 8600s better than Bob Latino VTA-ST70 ?

[Neville]

I just fired up my newly built 8600S. Thank you Victor for quick shipment. I have mostly stock 8600 as the father of Elekit intended except for Takman resistors. Will it up seat my Vta ST70? Let the fun begin....

[vkung]

TU-8600 is a SET 300B amp
VTA-ST70 is a PP amp
They are different in sound and purposes.

2nd review of TU-8600S will be available in Stereophile May edition.
2 times in 2 years (April 2019, May 2021). What makes TU-8600 unique?”

[Neville]

That's what makes it fun comparing apples to oranges.

Now that the 8600s is complete here are my thoughts about the kit. The parts are of high quality, but I was disappointed to find the 12a* tube sockets were not ceramic or porcelain like the 300b sockets and the headphone jack was a flimsy plastic piece. The instructions were excellent and the best I have encountered in DIY electronics. It was such a pleasure building this, I was sad when I fired it up. It has more parts than the Sun Valley EQ1616 but I really enjoyed this kit vs the mostly point to point wiring on the Sun Valley kit.

I am on a tight budget and consulted with Victor as to what my upgrade steps would be. I picked up the stock 8600S and the Takman resistors because it would be hard to unsolder the existing resistors - these Takman's have a tight tolerance and I did not have to create the little kinks in the resistor legs to get them installed. They were a little tight but they all got in and soldered. For the first time I used Cardas Quad Eutectic solder - it is pretty expensive but it melted like butter and all my solder was shiny and never had any bad joints.

I have Audyn True Copper Caps waiting to be installed but wanted to hear the 8600S stock and let it play for about 100 hours. I will eventually get the Lundahls too.

K so how does it sound so far ? For starters it does everything the VTA ST-70 does but I am hearing a more laid back soundstage with little more air around instruments.

What tubes am I running ? The Cossor 300B black plates have a beautiful blue glow, the 12au7 RCA Clear tops and Mullard NOS 12ax7 all paint a slightly warm image which is just the way I like it. I have never heard a 300B until now and it is everything I have read.

[Neville]

I am beginning to hear what the hype is all about. 16 hours into the stock build and I am hearing more of the actual instruments and occasionally “huh? Where did that sound come from”. At times some musical passages seem out of sync. There is more human love emotion in my music.

I find myself shaking my head not in disbelief, the music is there, the PRAT is on another level. Folks going to a Naim or Brit audio company will know what I am referring to.

I would have not bought this kit if it was not for all the glowing reviews and the good prices Victor sells 300b tubes at. I secured face plate and transformer cover. I don’t plan to make any changes, until I can afford the Lundahls.

Oh so how does the vta st70 feel about all this? It is a great amp and was my go to impress amp but will take a back seat for now. I don’t plan to sell it.

I have all the parts for an Aikido preamp but now will look at an Aikido tube buffer with zero gain as a preamp.

[rayma]

Which preamp are you using now? The amplifier has a 50k level control built-in.
A buffer may help with many tube preamps and sources.

[Neville]

I am manually switching inputs for now. I plan to build a 3 input that switches ground and signals. I have a ton of 6n1p and variants so hoping to build off that but might change to a tube that is cable/capacitance sensitive and with zero mu.

Between a 2V streamer and Sun Valley phono preamp, the Aikido preamp I planned is now overkill.

My speakers are zu omen DW mk2 as well as LSA towers.

[Neville]

Couldn’t leave it alone. I had bunch of porcelain 12a* sockets so replaced the stock plasticky with them. While it was opened I put in Audyn True Copper caps, fired it up and was not expecting the huge difference from stock caps to this. Neutral but slightly bright top end was gone and it became too warm. Detail was there in spades. Took out the Mullard 12ax7 NOS and Genelax brought little sparkle but not enough for me. Now have a Telefunken NOS 12ax7 and the balance has been restored mostly. I have Clarity ESA caps from another project I can try out if I still find this too warm. I can also add smaller caps in parallel to give it more sparkle but that will be last resort.

[watchdog]

I've completed my build a few weeks ago. I read somewhere that the True Copper Cap is only safe for speaker applications and that the True Copper Max should be used for high voltage coupling purposes. You may want to confirm this with Intertechnik.

I used Amtrans Golden Black capacitors in mine and they are absolutely lovely. I cannot recommend the Lundahl enough if you are considering your upgrade paths.

[Neville]

Thx for the mention of Lundahl - could you tell me what differences you heard? Yes, some have cautioned on Audible copper cap but so many have had no issues with higher B+ but I am keeping close eye on it.

For those wanting a sleeper 12ax7 tube I suggest checking out Psvane, it is from Shuguang, boy it reminds me so much of Mullard From Blackburn.

Starting on an Aikido tube buffer with remote volume this weekend. Unsure if I should remove pot from tu8600 or open it wide with this no gain preamp. Suggestions?

[rayma]

Leave the pot in until you definitely don't need it. You can just turn it to maximum for now,
if you need all the gain available in the amp.