The Latest Waypoint

John Frum

Secret Society Member
A couple of months ago, I tore down my main system, in anticipation of changes that haven’t yet materialized.

Yesterday, tired of having no music downstairs, I threw a little something together, incorporating new speakers, amp, and DAC.

The Almarro A205A MkII is my first turnkey foray into single-ended amplification. I’m still rolling tubes through, and spent the majority of the last evening with a Telefunken ribbed-plate 7025 and Motorola-branded smoky Mullard EL84, courtesy of the stash.

Speakers are Coral 12TET-1 triaxials in 9 cu. ft. custom cabinets, hauled to the US on Uncle Sam’s dime in ‘66.

DAC is an Arcam irDAC-II jack-of-all-trades. While it’s technically current-production, a 2016 design is ancient in DAC-years. I found this one new in box for less than one-tenth of retail and couldn’t resist.

Speaker cables are tinned-end Belden 5000UP and analog interconnects are Belden 1505F with Belden ProSNS RCA plugs.

CD transport is still my Marantz CC3000 changer. My workmanlike vinyl rig, consisting of Technics SL-1600, Ortofon 2M Blue, and Pro-Ject Phono Box S, remains unchanged.

The results are good, but not great. There’s a huskiness to male vocals I’d like to smooth out, imaging is poor, and the sound isn’t as dynamic as I’d like.

In short, it’s a meaningful step backwards from where I was in January. I will play further with tube-rolling and, as space allows, speaker placement. I’ll also give myself the reality check of comparing the CDP’s output to the DAC. But the speakers are placeholders, and I’m not going to drive myself too crazy “fixing” this system until I have my Altec 604-8G in 620ish cabinets ready to take their place.

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Redboy

Knobophobe
The results are good, but not great. There’s a huskiness to male vocals I’d like to smooth out, imaging is poor, and the sound isn’t as dynamic as I’d like.

In short, it’s a meaningful step backwards from where I was in January. I will play further with tube-rolling and, as space allows, speaker placement. I’ll also give myself the reality check of comparing the CDP’s output to the DAC. But the speakers are placeholders, and I’m not going to drive myself too crazy “fixing” this system until I have my Altec 604-8G in 620ish cabinets ready to take their place.
That looks like a fun setup but I'm fairly confident in saying that your 604s, when they arrive, will change the equation significantly!
 

Ernie

This was Nikki.
I have the same amp, and run with Matsushita EL84s. These tubes are made on Mullard tooling.

You might find that changing the 12AX7 provides more dramatic changes than does changing the power tubes. I have a Matsu there, as well. Warm, clear, no huskiness, but lots of LF. Imaging is good, and dynamic. The Mullard family is akin to a polar opposite, in the A205. There is lots of middle ground to explore. You might want to consider the Mazda "silver plate", if you have one. Otherwise, you can tailor the sound with whatever else you have.

My little amp visited billfort's audio den, and performed surprisingly well on his big Altecs. I would note that both Bill and I use speaker cables of a much smaller gauge than your 12awg Belden. That may have an impact on your sonic presentation. Mine is Chord Carnival Silver Plus. Bill's is a single run of small gauge enameled magnet wire.
 

writethis

Junior Member
Bill's is a single run of small gauge enameled magnet wire.

If a guy wanted to experiment with magnet wire, any helpful pointers or warnings? This would be an 18’ run, the system in question is NOT low power/high efficiency. This would connect a pretty big Pass class A to KEF 105, in case that affects any recommendations. Thanks in advance!
 

Ernie

This was Nikki.
Bill has low-power SET amps (300B, 2A3, 45(?) etc) I took my Almarro A205 to give a listen to Bill's big Altecs on my little amp.

I don't think I'd want to risk a thin strand of wire on a high power/low efficiency set-up. You could always try it, and check that the wire, nor the amp is heating up, with extended playing.
 

writethis

Junior Member
Thanks Ernie. Opportunist that I am, thin wire (and Duelund) has always seemed like an interesting direction to explore. Still does, but not in the context of my system I guess.
 

John Frum

Secret Society Member
Tube rolling is rewarding on the Almarro. The step from the JJ tubes the amp came with to the Mullard and Telefunken tubes I was using last night was noticeable.

The combo I’ve landed on tonight (RCA black plate 12AX7 and Sylvania black plate 6BQ5) addresses most of the complaints I had last night, and the system sounds gratifyingly like real music. Two thumbs up; would bottom-feed again.
 

Audionut

Next Round Is On Me
Tube rolling is rewarding on the Almarro. The step from the JJ tubes the amp came with to the Mullard and Telefunken tubes I was using last night was noticeable.

The combo I’ve landed on tonight (RCA black plate 12AX7 and Sylvania black plate 6BQ5) addresses most of the complaints I had last night, and the system sounds gratifyingly like real music. Two thumbs up; would bottom-feed again.
Thanks, I have Almarro on the brain again!
 

Thermionics

Post Whore In Training
Tube rolling is rewarding on the Almarro. The step from the JJ tubes the amp came with to the Mullard and Telefunken tubes I was using last night was noticeable.

The combo I’ve landed on tonight (RCA black plate 12AX7 and Sylvania black plate 6BQ5) addresses most of the complaints I had last night, and the system sounds gratifyingly like real music. Two thumbs up; would bottom-feed again.
I'm a big fan of Sylvania or RCA black-plate 6BQ5 tubes (and RCA black plate 12AX7 are nothing to sneeze at, either). Another tube you might want to try would be an NEC 12AD7. I'm becoming a big fan of this tube.
 

John Frum

Secret Society Member
Checking back in, I can’t say that I’ve tried every tube or combination the vast hoard can supply, but I keep going back to...

  • Sylvania (Baldwin yellow tip) black plate 6BQ5
  • Raytheon black plate 12AX7A

I wind up missing either when I swap them out. Both dynamic and resolving.

I should mention that I’ve swapped out the Coral triaxials for Zenith 49CZ802 console woofers. Testing the t/s parameters proved to my satisfaction that it’s the same driver as the lauded 49CZ852. These are perhaps the best example I’ve yet heard of audio equipment holding up against its internet hype.
 
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