Wednesday, March 23, 2022

Review: A Tale of Two Schiits - Mani 1 vs Mani 2 phono preamp

(photo from Schiit)

I've been using the original Schiit Mani 1 phono preamplifier for some time.  Its sole purpose has been to provide the needed amplification and equalization for my second turntable, the Dual CS5000.  It has done well plugged into the line section of the Audio Research SP8, which has a phono section that is used for the primary turntable, a Thorens TD309.

To be fair, the Mani is a budget phono stage so I could put up with the slight graininess, mid-fi resolution, and the general lower fidelity.  For all the Mani 1's faults, it is still better than a lot of stock phono sections found in budget receivers, preamps, and integrateds.  And given the mostly background music it was used for I had no complaints.

A recent visit to the Schiit Audio site and I saw that a second version of the Mani has been released, this one using a different op-amp and it was also direct-coupled.  The case looks exactly the same but the dip switches on the bottom have changed, allowing more settings for MM and MC cartridges.

To cut to the chase, compared to the old version, the new Mani 2 is more detailed, faster, has better resolution, deeper bass, and higher overall fidelity.  It also images, left-to-right in a fashion that will be most pleasing.  It isn't perfect - nothing is! - but it does swing at a higher than the $149 (black face model) price point suggests.

Where the Mani 2 ultimately fails - compared to the Audio Research SP8 or the Classe Five - is inner detail and that certain "you are there" magic that I've heard with these more expensive units.  The soundstage of the former is also flatter without that depth I've come to expect.   However, to be fair. the Mani 2 does strike awfully close to better preamps making my budget Dual CS5000 sound a lot closer to the combination of Thorens TD309 and the ARC SP8 phono stage.  Depending on your front end, amps, and speakers, this difference may not matter at all.

 As always your mileage may vary depending on your front end, setup, and preferred listening habits.


System:

  • Dual CS5000 with Ortofon OM20 and an aftermarket Shibata stylus
  • Thorens TD309 with Ortofon 2M Bronze
  • Audio Research SP8 with vintage Mullard 12AX7s 
  • Eico ST70 "Frankenstein" amplifier with 6AR6 output tubes
  • KEF R500 speakers
  • MIT interconnects
  • Cardas Twinlink speaker cables


Thursday, September 2, 2021

Short Review: Dynaco A-25 VW loudspeakers

 

The Dynaco A-25 is a 2-way bass-reflex loaded speaker sporting a 10" woofer and a soft dome tweeter.  I picked up this pair at a half-off day estate sale.  I wasn't, however, expecting much since my experience with vintage speakers has been mixed.

To my surprise, the A-25s really capture the midrange in a nice and pleasing manner.  Yes my (larger) KEF R500s can pump out more bass & treble, do dynamics better, and throw a deeper soundstage; but still these old Dynacos have a certain magic that is hard for me to put my finger on.  Perhaps it is the nice all tubed front end I have, but these vintage speakers are just relaxing to listen to.  They do jazz really, really well; hard rock not as nicely due to their dynamic limitations.

So if you see a pair of A-25s for a good price, check them out.  They would be great in a small system with a low-powered tube or Class A solid-state amp; along with a suitable preamplifier.  They don't do all of the hi-fi tricks of something more exotic, but, like the Dynaco PAS and Stereo 70, capture the midrange depth and bloom a lot better than many, many modern budget components.

Thursday, March 11, 2021

Turntable Basics and Buyers Guide


 Here is a short video I made about buying turntables; geared toward beginners or anyone looking to upgrade to a new record player.

Friday, February 26, 2021

Review: a Frankenstein Eico ST-70 tube amplifier

 I bought this strange modified amplifier on Ebay. It looks as if someone took a stock integrated and modified it to be a basic power amp. Gone is the normal set of controls on the front plate, replaced with a generic black panel and power indicator light.


[​IMG] 
A peek on top of the grille - what is inside?

[​IMG]

Of course you know - you read the title of this post! Someone took an Eico ST-70, removed the preamplifier portion and converted it to use 5881s instead of the stock 7591s.

[​IMG]

Since I didn't have any 5881s on hand, I modified this amplifier to use the military 6AR6. Since the 6AR6 has a completely different pinout (and bias points!) it took an entire rewire of the output stage, along with more negative bias than the stock circuit.

[​IMG]

I also changed the power supply with new electrolytic capacitors for the main bucket, 6SN7 phase-splitters, and 12AX7 input tube. I also added a little 1.5H Dynaco choke to reduce the B+ ripple. After a little troubleshooting, and bias modifications, I finally got this amp to work; with 40mA per output tube. 

So how does this pentode output Frankenstein weird output tube sound? Even with old Russian 6N8S tubes, surprisingly good. Bass extension - with the large output transformers - is really deep. And there is the old tube midrange and smooth treble thing happening. Maybe it's been too long with an SS (Aleph J clone) amplifier, but this little push-pull tube amp is quite magical.

Chet Baker Sings, for example, really is holographic - for a mono recording - with his voice and trumpet sounding natural and forward. Compared to the Aleph J solid-state amplifier, music is more relaxed but, at the same time, more dynamic. The tube amplifier sounds way more powerful than its approximate 30 or 35Ws per channel.

I'm surprised that the KEF R500s work so well with this vintage Frankenstein; you never really know what you are going to get with modern speakers.

Once I get over the excitement of having a new amplifier, I plug in some old Zenith 6SN7s that I have on hand. Maybe things will get even better-better.

 

 

Thursday, January 28, 2021

Short Review: a Hafler SE-120 amplifier

 


This is a Rockford Corp era amplifier good for 60WPC; made to be _not_ user friendly versus the kit amps of yore. This one looks to have been around the block though some face plate cleaning helped to remove a bit of yellowing.

The amp sounded a little tired so I went in and replace the main electrolytic capacitors, the input caps, and two of the smaller power supply rail caps. Needless to say getting to the underside was very frustrating with the number of screws, removing the output mosfets from the heatsink, and pinching the nylon standoffs to free the PCB. In the end I also checked the bias, cleaned the RCAs and speaker jacks.

After my work: Overall it is a nice sounding budget amp - to my ears a little warmer than something like an Adcom 535. Good bass, and more of a rock 'n' roll sound than say the Musical Fidelity. My Aleph J clone is a bit more refined with a touch more detail and "space" around the instruments. Though all three amps are "warm" none of them exactly sound like a tube amp. An old Frankenstein Eico ST70 - modified to be a power amp with 6AR6 output tubes - I have kicking around has a presence and sense of dynamics that I just don't hear with these (admittedly low powered) SS amps. Nonetheless I could live with the Hafler if I really needed a compact amplifier.