Done!

[Ivan303]

Couple of fiddly broken wires and a pair of 'extra' resistors at the end, but nothing fatal.

In the system and running.

How does it sound?

A bit more ''forward' than the 'laid back' 12AX7  Consonance based DIY HIFI Supply 'Cole' I've been enjoying for 20+ years.  But also maybe more 'information' as well.  Break-in?  That's easy as my system is on most every day.  Maybe even do a 24/7 this week as see what happens.

Going to need longer interconnects to run both phono stages (old and new) at the same time as space in the rack is now gone and the phono pre and the line stage are at opposite end of the rack.  Plus the cables from the tonearm to the step up and the step up and the phono preamp are, by choice, kept short.

But I'll give the Eros 2 a week to break-in before I do A:B testing and that with a couple audiophile friends with 'younger' ears.

Also plan to resist the temptation to roll tubes and swap caps for at least a month.  With all the active loads/shunt regulation/constant current sources used in top-end Bottlehead gear, tube rolling can be a bit of a disappointment anyway.  OTOH, low noise and low distortion are maybe worth the price?

How will it stack up against other top-of-the-line tube based phono-preamps?  Might get a chance to find out soon enough.   Local audiophile has a collection of them, from 20+ year old George Wright phono preamps (two) to newer, modern multi-thousand $$$ stuff as recently reviewed in Stereophile such as the PrimaLuna EVO line. He's got a vinyl only rig (no CDs or streaming) with a multi-thousand $$$ VPI table, 300B monoblocks of some sort and Tannoy speakers. 

He's bringing some of his best vinyl over next week to hear the Eros and I plan to take the Eros over to his place to see how it compares to some of his various pieces.

Based on what I'm hearing right off the work bench, the Eros 2 should do fine.

[hmbscott]

Congrats! It's an awesome piece of gear IMHO. I will be very interested in your comparisons to other tube stages.

[Ivan303]

Had the chance to do a good comparison between the Eros 2 and my 25 yo DIY HIFI Supply 'Cole', with the assistance of an audiophile friend who's ears I trust.

Found a 'sealed' copy of Alan Parsons Project Tales of Mystery and Imagination which we ceremonially unsealed.  Perfect vinyl after years in the packaging.

Verdict?

Tough call. 

DIY HIFI Supply 'Cole' is a more traditional  tube-PS, 12AX7 (high-priced NOS) phono preamp, constructed using upgraded parts (silver mica caps, high end resistors, etc.).  Been my favorite for years with nothing else I've tried coming close. And certainly nothing solid state.

So after a week of continuous power on, how does the Eros 2 compare?

Not that different.  Audiophile friend preferred the Eros 2 as more to his liking.  Better resolution, flatter frequency response, more dynamic and (maybe) more bass and (maybe) more like the SS system which he has at home and is used to.

Me?  I'm torn. 

I prefer, by a bit, the more relaxed, analog sound of the older preamp.  Not surprising for a toobs-n-horns guy.  But the increased resolution and the added dynamics and forward presentation (if that's what we were hearing) are a nice addition. 

I promised myself to go with this piece for a month without even thinking about possible upgrades.  Which I will do.  Then revisit the 'Cole' after that month as see if it's a forward or backward move.

Then, if there are still things I prefer in the older preamp, start looking at upgrades to perhaps bridge the gap.

[Ivan303]

So a month has passed.  Time to look at possible improvements?

Very fine phono pre-amp in stock form, to be fair.

But a box full of NOS, ridiculous-value (today), 6922 types beckons. Have had these tube for years, from back when I could purchase a NIB/NOS 6922 made by Amperex or Mullard for about $25 from Salt Lake Instruments.  And Siemens CCa for about the same. Never had a piece of gear that used them and bought them as they were reasonably inexpensive then and I expected to own something that used them someday.

Now, 20+ years later...

I measured a few of the 6922 types in my tube tester and the CCa's all read as new (or better) so I chose the one with closest halves (94/95) and popped it in.

Not jaw dropping but just a bit more clarity while keeping in mind that clarity is an Eros' strong point.  Thankfully not 'etched' or 'detailed' in a bad way.  Still a bit 'forward' compared to the 12AX7 based phono it replaces but that's to be expected.

Again, not a HUGE difference and not enough to justify what is now a $200-$300 tube (on Ebay yet) or $495 each from Tube Depot (who doesn't have any), but clearly a step up.

https://www.tubedepot.com/products/siemens-halske-cca?srsltid=AfmBOor_LPz4BmZmZBDuzrIRD-0gxHiWtFxTVj3v8nmQOuno_IFHYt4N

Just not a multi-hundred dollar step up.

Would expect pretty much the same with an EF86 upgrade; a tube I have never owned.  Even the Telefunken EF86 at $hundreds$ per pair?  Some improvement maybe?  Buy a couple off Ebay and find them noisy?  Maybe later.

If one is into tube rolling, all those active loads, constant current sources and shunt regulators are going to make for only small changes, if any, assuming all good tubes to start with, of course. A good thing, as NOS is more and more scarce and expensive.

I'm sure the smart guys here, named Paul, can verify if I'm correct or just losing my hearing?

The series output caps are next up. Those crappy little 1 uf Solens gotta go!

Maybe try VH Audio V-Cap ODAM as they have a reputation for 'oil cap' smooooothness while still letting all of the musical detail shine through (see graphic below).  Maybe upgrading tubes make only small differences is sound but a couple $hundred$ in caps might improve things a bit?

We'll see.


Rebuilt custom LENCO - Sorane 1.2 arm - HANA Blue cartridge - Cinemag step-ups 

[Paul Birkeland]

EF86s make a nice difference, but some of the prices are a little insane.  I've seen the same "crappy" Solen caps we use in Stereophile class A rated equipment, so YMMV.  The voltage present in the Eros is nice and low, so there's a ton of flexibility in terms of what you could put there, and we left a lot of room to accommodate bigger caps. 

 

[Doc B.]

I've kept a pair of Tele EF806S and an Amperex 7308 that I like for use in the Eros/Tube Repro circuits over the years. But I have to say that the Soviet surplus stuff that we usually supply in the kits is not that far off for the difference in price. It's never about "this is definitively superior". It's about seasoning the stew to taste.

[hmbscott]

I recently installed a pair of Telefunken EF 86 red tips (used - tested as new) purchased on  Ebay for $200 for the pair and a NOS E188CC BVA Mullard TV7 B/U also on ebay $50, which replaced the stock tubes. I thought the set was a nice upgrade and worth the price. I also upgraded the output caps from Audyn Cap Plus 1.5uf to Audyn True Copper 1.0uf, and the shunt reg board Dayton Audio 0.10uf caps with Solen 0.10uF Silver Sound MKP, the caps made a less obvious improvement. After letting that all break in for a few weeks. Then went thru and replaced all the signal path resistors with Vishay VAR Z-Foil (including C4S board caps Paul recommended) and the RIAA caps with hand matched Dayton Audio DFFC-0.01 0.01uF (film and foil). Another subtle improvement. But all said and done, the net improvement was substantial. Total cost was a bit over $700. It definitely increased my sense of engagement and has me playing more vinyl. That was followed by a cartridge from 2M Bronze to a Hana MH, another nice improvement, but between the upgrades to the Eros and the cart, I'd judge the Eros upgrades made a bigger improvement.

[Ivan303]

I've seen the same "crappy" Solen caps we use in Stereophile class A rated equipment, so YMMV.   

Wouldn't doubt it.  Seen some awful stuff inside some high end audio gear.  But then I'm guessing that some Bottlehead gear is the equal in sound quality of Stereophile Class A, so there you go.

My Monamour mono blocks are the equal of any SE triode amp I've heard for quite some time, both in sound quality and in quietness.  Quiet being a big deal with 106db horns.  EML mesh plate tubes help, and even a Solen coupling cap upgrade!  OK, a green teflon Solen caps replacing the white not-crappy ones..

In stock form the Eros 2 would be hard to beat at multiples of it's price.  Absolutely dead silent.  Would I like a bit 'warmer' sound?  Yeah, maybe, if I didn't have to trade it for clarity and dynamics and all the little things that one can hear that some folks don't even know is on the vinyl records they've had in their collection for decades.

Series output cap upgrade is my hope. 

We'll see.

[2wo]

I am using a Solen Silver as the Perafeed Cap in my latest 45 amp and it sounds good

[Ivan303]

EF86s make a nice difference, but some of the prices are a little insane. 

Any suggestion a bit less $$$ than the Tele EF86/EF806S?

Would prefer something where, should a tube turn out to be noisy I'm not out a couple hundred bucks. 

Not that it's a big deal as I'm happy as it sits and I've got plans for the series cap at the output. At $100 a cap I suppose $100 a tube is not unreasonable

And even then I'd have less that $1500 invested in a phono pre that is in line with those selling for several times more.

Next is Cinemag CM-1254 installed in the chassis to replace my DIY stand alone step-up box which uses the cheaper CMQEE-3440AH but is quiet as a mouse and beats the Denon step-ups I've tried by a mile.

That will be the end of the line and with upgrades in EF86 tubes and series output caps less than a $2000 total investment.   Bargain basement prices in today's High End Audio world.

[Ivan303]

After month of listening as-is, a 6922 upgrade to Siemens Cca and some improvement. Not as much as the $$$ value of a NOS Cca in today's market, but I can hear a difference.

Then an output Cap Upgrade: V-Cap  Oil Damped Advanced Metalized (ODAM). 1uf 400V (pictured below).

THAT is an upgrade.  A $150+ upgrade, but well worth it (IMNSHO).  About the price of a pair of NOS tubes (and cheaper than a NOS NIB Cca) and should last a LOT longer.

Improvements in sound across the board. 

I found, out-of-the-box, the Eros 2 was just a bit 'hard' sounding when compared to the 12AX7 phono pre I've enjoyed for the last two decades. Perhaps more detailed and more 'up-front' as well.  Certainly not 'laid back' and perhaps even a bit SS sounding?  Ok, just a bit.

Most all of that is gone.  Still a bit more 'forward' than my old, mellow, tube phono preamp, but not in a particularly offensive way.  More of just about everything good while most of the 'hardness' is seemingly gone.  The clarity and detail remain, without any of the annoying 'detail' that sometime accompanies more 'detail'.

Even think I'm hearing improvements in sound stage, but guessing mostly hearing more of the small details in the upper registers on the extreme right and left that are now somewhat more noticeable.   

Spin records for hours without 'listener fatigue'?  That's the true test.  We'll see.

So how does it now compare to the old 12AX7 based phono preamp that's spent the last month sitting on a shelf and disconnected from the system? 

We fired it up for a listen.

'B' side of Jethro Tull 'Aqualung' (My God) starts out pretty enthusiastically!  Especially the  'Steven Wilson Mix' on180 gram vinyl.

Still a great phono preamp considering it's a 20+ years old, DIY HIFI Supply 'Cole', built from a $400 kit and based on a Chinese (Opera Audio) commercial design.  OK, upgraded components, silver mica caps in the RIAA and the best NOS tubes and all that.

Music is all there and sounds good but it's not jumping out at me. A bit laid back?  Thin veil? 

Switch back to the Eros 2 and we've upped the enthusiasm factor by a notch, maybe two, even after reducing the volume (a lot) to compensate for the extra gain of the Eros 2.

Back in the day, I plugged in many decent tube (and SS) phono preamps into my system, but none I liked better that the old DIY HIFI Supply 'Cole'.  That's including the EAR834P which was considered hot stuff 20 odd years ago, and a couple of George Wright efforts.

But the Eros 2 is here to stay.

And the VH-Audio ODAM caps are a HIGHLY recommended upgrade. 

Upgrading the 6922?  Not as much as would be expected.

EF86 upgrade next? Yes, but is the Tele worth it?

Cinemag integration?

Stay tuned.





 ,

[Ivan303]

Tube rolling!

My prior upgrade of the single 6922 with a Siemens CCa produced some, but not a great deal of improvement.  Certainly not when considering the price of a single decent NOS CCa in the current tube market.  I've had these tubes in my collection for decades and this is he first unit I've owned that used that tube type so no additional expense on my part.

So now it's time to look at the EF86s. 

In fairness, the Winged 'C' Russian tubes provided must be quite ok, as this is a VERY good sounding phono preamp right off the bench with stock tubes.  Yes, upgrades to the output capacitors made for a big improvement, at least to my ears.  Mellowed the hint of 'hardness' I was hearing in the stock unit and relaxed the sound a bit and without any loss in clarity, which is this unit's strong point, at least to my ears. 

After a bit of work, I acquired 2 each NEW/NOS Telefunken EF86, albeit at ridiculous prices.  Took a while to find,  but a few phone calls to old contacts in the business worked out well.  These are the real deal (pictured below).  Again, at a ridiculous price. Half the price of the whole kit!  But then the stock kit is likely the equal of an off the shelf, commercial tube phono going for 3-4 times the price. So half its price but NOT half its value!

Verdict?  Worth every penny!  Harmonic richness is up quite a  few notches. Not a hint of nastiness anywhere to be heard, but then there was none with the old tubes.  Re-issue of Procol Harum's A Salty Dog was a revelation.  45 rpm 'Julie Is Her Name' never sounded better.

My advice to anyone building this kit would be:  First upgrade the series output caps with the VH Audio V-Cap ODAM Series Capacitors.  Less than $200, and worth it.  Forget the 6922 unless you can find really fine NOS for a reasonable price.

Then consider upgrading the EF86.  Especially if you have a really high end vinyl rig with a better-than-decent cartridge.  The Eros 2 with these two upgrades will do justice to any 5 figure TT/Arm/Cartridge combo in a high end system.   

It's that good.