Thiel Owners

beetlemania

I totally hear you :) Then again, you had the invaluable benefit of being guided by perhaps the most qualified person on Earth. This, I think you will agree, is an unusual circumstance.

I was on my own for my last rebuild, short of conjuring a séance with Arnie Nudell. I don’t have quite all the skills to modify / redesign 5-way, 7-driver crossovers with any expectation of actually improving them.

I stand by my earlier comment as it applies to most enthusiasts; barring an expert guiding us, I do believe replacing same with same is the course of action most likely to yield success.

To put things in perspective, 14 out of 14 electrolytics I replaced tested perfectly fine, both ESR and capacitance, despite being almost 45 years old​. I did find three bad resistors and one bad rheostat though, which I wouldn’t have expected.

I thought this might be of some use. But if not, it is some good news for me. I got a  used BAT VK 250 from TMR. They sent it in to BAT in November before I was even looking at it. BAT checked it out and replaced the big caps with the news ones they use in their amps. 

Anyway I have had it for three weeks. This is a sweet sounding amp so far. It sounds nicely transparent and warm at the same time.  It has the right warmth and body, a feel that their is a real whole human body playing/singing from the gut up, and real whole body instrument sounds. And it does the disappearing thing, where you just see into the performance and forget about the speakers. Nicely naturally detailed that I enjoy hearing. Seems like a perfect balance for me. It shows no signs of lacking power. And it seems to fit the Thiel 2.4 sound profile perfectly for me. Extremely well balanced from top to bottom, so nothing sticking out but the connection to the artists. The plane of the sound starts at the speaker line and goes back from there. You get the excellent intimate perspective when recorded, the pace rhythm and timing Thiel is excels at, and the really good macro part that impresses in the dynamics.

If somebody lives on the edge and wants a bottom up speaker sound or a top down sound this may not work, but maybe.  

marqmike

Nice score! on the B.A.T VK 250.  Good to read that you like the VK 250 / CS 2.4 combo. What other gear and cabling rounds out your System?

Happy Listening!

Happy Friday! All

devin - Replacing like with like components is certainly the safest. Many folks underestimate the intricate co-dependence of all the elements. Even layout changes affect the subtle outcomes. Keeping values at original levels is a good start, but various parasitics also matter. The frequency response is rarely changed in significant ways; but time/phase generally is.

You may remember the maddening months to years delays between Thiel product announcements, or even live displays, and their actual release. Most of that time was tweaking, mostly in realms more subtle than most designers would pay attention to.

In our DIY / rework world, the largest trap that I’ve found is subbing foil for the original wire inductors. Foil is indeed a more pure inductor, but its parasitics are so different from wire that considerable xo tweaks would be required to re-settle the circuits.

The safest bet is subbing in Mills MRA resistors for Thiel stock. Another safe and surprisingly effective tweak is replacing any electrolytic cap with 2 x half-value cap. The ESR and other anomalies are reduced by half, plus if you turn one cap backwards, end for end, other anomalies are cancelled. If there is a bypass cap (like Thiel’s yellow 1uF), that can be stacked to make a triangle for a single field.

Replacing caps, especially larger values is quite costly and sometimes demands circuit tweaks. It’s not hard to throw as much cost into upgrades as the entire production budget of the original speaker. Not for the faint of heart.

TT