Warming up Eros sound signature

[DesignTaylor]

I've been tube rolling on my Eros for about year and finally settled into a nice combination. Then, recently I switched over an MC cart (Denon DL-301ii) and added a Cinemag based SUT. The clarity is amazing and the bass is huge, but I've lost a little oomph and warmth in the mid tons.

I'm wondering:
A) which tube(s) (input, output, regulator) contribute the most to the Eros' sound signature
B) does anyone have any specific tube recommendations to achieve what I'm after?

Thanks!

[Doc B.]

Try Mullards for the EF86 and 6922.

[DesignTaylor]

Thanks Doc. In the EF86 slots, I'm currently running Holland made Mullard military 2901's and have a pair of Eico branded Mullards Made in Great Britain  I might audition. For the 6922 I've got a Matsushita / National PCC88 which has some pretty nice mids. I guess I'm on the hunt for options that are real fat and warm. Also curious if you think the input or the output tubes end up doing more of the coloring?

[Doc B.]

With low level signals everything has an influence on the sound. You could try different cables (perhaps Mogami) and output caps (maybe oil) as well as different tubes. You might also try changing the cartridge loading.

[DesignTaylor]

Thanks Doc, lots to look into.

[DesignTaylor]

So for the short term, some tube swapping seems to have done the trick.

The biggest difference was found by swapping in a Tngsram E88CC for the 6922. A little additional warmth and smoothness was added by trading the EF86 Mullards for some Amperex Bugle Boys.

The unfortunate outcome is that I now know enough about capacitors to be extremely interested and very dangerous

[Deluk]

If what's been lost has been caused by introducing the Denon and SUT into the system, perhaps they weren't the best choice. It's all compromise but changing more things to bring back what you've lost by a quite major change to the system can be both costly and frustrating. As an aside, just repositioning the speakers can often bring about useful changes for the better. If you are lucky enough to have a dedicated listening room a rethink on the layout and the furnishings might be useful.
For some further thoughts on the Denon and SUT https://theartofsound.net/forum/showthread.php?43376-Denon-301-mk2

[johnsonad]

The only capacitors that you can adjust are the output. Try some paper in oil and then try Teflon film and foil. Between these and the tubes you should be able to find a combo that works well for your taste.

I use a pressed plate Amperex Bugle Boy 6922 and Tele EF86’s with Teflon film and foil outputs.

[DesignTaylor]

@Deluk - Wise words indeed. With any new tweak to my system, I always take the time to do some listening test comparing before and after. As you noted, not every new addition works out (even if it is good on paper AND you are really excited about it). Sometimes the best move it to return it or sell it on to someone else. In this case, I'm excited by the newfound detail and clarity that the cart and SUT are extracting. Just a matter of balancing it back out.

@johnsonad - Thanks for the capacitor tips! Always helpful to hear where people have ended up with their own configurations.

[maryc27182]

Aaron, those are the Solen S3Q, right? I'm pretty sure I read a post of yours back in 2017, then followed your lead, and put those in my Eros.

As for tubes, I'm currently running the G.E.C. CV4085 and Amperex 7308. I had to do some shopping around to find the G.E.C. at a not-insane price (but they were still way more expensive than the Russian EF86, which are very good, imo.)

Mary

[johnsonad]

Mary, you don’t have to spend a fortune for tubes in this amp. If you have some local HAM’s, hit them up. I got most of my 6922’s from old oscilloscopes for free. Local swap meets can yield a lot of great finds.

For EF86’s, if you have a stock Eros build, my favorite cheap tubes is the 6br7. You would need to rewrite the socket but to my ears it sounds as good as the tele’s and they are my personal favorite.

Another quick thing you could do is bypass the output capacitors with a Russian PIO or something similar. You could put them on alligator clips vs soldering them in and see if it helps. The Teflon’s might me a little sterile for your taste. I love their clarity and detail. My other favorite in the Eros build is the older style Auricap.

Keep us updated on what combo worked best for you.

[maryc27182]

Almost a necro-post--kept meaning to respond.... However, here we are.

As I wrote, I replaced the caps to the teflons you recommended--I like them very much. And I used the tubes I mentioned, and those G.E.C. are pretty sweet. I've also kept the Amperex 7308 in there since I got it about a year ago.

I have, as well, destructively disassembled a Navy oscilloscope that a friend gave me. It was fruitful, and I'm using one of those Sylvania 12AT7WA triple mica in an RH84 amp I just finished.

Mary

[johnsonad]

Nice job Mary! It’s pretty easy to tweak the sound signature of the Eros to make you happy. I’m glad that you found a sweet spot for you.