Preamplifier options - seeking help to determine which one


Hello everyone

 

I have made a number of posts already and I hope you are not yet annoyed with all my beginner questions. 

I will proceed with a Yamamoto amplifier and I will need a preamplifier with a phono stage that allows my Denon 103R. 

Yamamoto makes two preamplifiers

1) Yamamoto Sound Craft CA-03 Vacuum tube preamplifier with built-in tube phono encoder 

2) Yamamoto Sound Craft CA-04 Tube Type Line Level Preamplifier

Ad. 1: This preamplifier is more expensive that CA-04 and it comes in two versions: Double volume adjustment or Level Attenuator - the latter being a bit more expensive. What is the difference here and what do you recommend me to choose? 

It allows for MC pickups but "Since the maximum output is about 28V, it can be used not only for MC cartridges, but also for MM cartridges with large output and MC cartridges with high output" - will it be a problem to use a Denon 103R with low output? Will it be necessary with a SUT to make the Denon 103R to perform better?

Ad. 2. This option is less expensive. It seems more simple but I'm not sure what the difference to the CA-03 really is. I guess I would need a external phono stage or a SUT to allow my Denon 103R in the system.

 

Bonus question: I use an Apple Airport (yes, I know) to stream from Qobuz. Can I use the Airport with both options using an AUX or CD input just as I'm doing with my current Sansui AU 9500? It's just to be sure.

 

Thank you very much. I hope you can help me elaborating on the differences and explain the different terms (attenuator, line amplifier, etc.). 

 

apollinaire

Showing 3 responses by spindoctor0470

Hello and I've just read your post hence the delay in replying.

I owned and loved a Yamamoto A011 (VT52) amp for nearly 9 years.

I've also listened to both the Yamamoto C03 with the 'normal' and stepped attenuators.

I have a few observations and opinions which you can follow or Ignore as you please. The A011 actually puts out about 1.8 watts, before clipping, as measured on a 'scope with load resistors, not 3 watts. It would simply not drive my Audio Note ANJ speakers at all! I did get a very quiet sound out of a pair of AN Es which are nearer 92db rather than 98db. I think you have to use this amp with a pair of easy-to-drive speakers of at least 100db. I have a pair of Lowther back-horn-loaded TP1 speakers which are 105db and play at rock concert levels with less than half a watt! The VT52 amp was brilliant with the TP1s BUT did hum in between tracks (less than 1mV hum) Speakers around the 100db mark will sound great and not have noticeable hum so are Ideal. So the likes of Klipsch Heritage Cornwalls or bigger. Maybe Zu audio speakers, Most Lowther BHL speakers, Avant Guard, or other speakers with an active bass?.

  The Yamamoto CA03 is a very nice phono stage/pre amp. I've had to clean a friend's  stepped attenuator CA03, a few times, to stop loud clicking noises caused by dc on the attenuator burning the contacts. The 'normal' attenuator CA03 doesn't have this problem and sounds just as good so that would be my choice (and it's a bit less expensive). 

Oh and I still have a complete set of NIB and NOS valves for the VT52 amp

and the CA03 preamp, They would be for sale if you wanted them.

Hello again, Firstly apologies for the mix up. I quoted the wrong model No from memory! I owned a Yamamoto A010, the VT42 SET amp, not the A011, 2A3 amp. I bought the A010 without the VT52 power valves. I asked for 8 ohm and 16 ohm speaker taps but Shigeki Yamamoto Insisted that I had to choose one or the other! However, the amp arrived with both 8 ohm AND 16 ohm taps! Shigeki also supplied the amp with 4 NOS 'coke bottle' Hytron 80 rectifiers and two Siemens C3M input tubes. A valve/tube pal had a large stash of VT52s, I bought 2 pairs of NIB Hytron 1943 vintage VT52s. I bought another two pairs of NIB Sylvania VT52s off a US seller and two pairs of Tungsol VT52s off another US seller. I sold the A010 with a pair of lightly used Sylvania VT52s and Hytron VT52s. I still have the other unused pairs of VT52s, so 4 pairs in total. Did you know that the A010 will also happily use 6A3 tubes in stead of the VT52? These are what I mainly used as they give a bit more power and are really nice sounding valves (a bit easier to get hold of too) The A010 uses constant current heaters so the 6A3 heaters run at about 6,5V which is fine. you get about 55mA on the meter instead of about 43mA, with VT52s. I had a pair of the cheaper ANJs and had a pair of KIT 3 ANEs. AN rate the dearer ANEs at 98db but reviewers warn that they are nearer 93/94 db. If you stick with Yamamoto I would be tempted to get the KT88 A03 12w SEP amp? The tubes are alot easier to get and it would be a better match, power wise. Another valve amp that I think works really well with ANEs is the smallest Leben EL84 intergrated amp. Also try and hear Audio Notes own EL84 and EL34 push/pull amps.

 

 

 

 

 

 

Hi again, A friend of mine Is/was a Yamamoto dealer and loaned me an older A08 45 SET amp to try. I loved it but thought that it struggled a bit, dynamically, on large Orchestral climaxes, with my 100db Lowther 'Fidelios'. Because I had a pal with a supply of VT52s, I went for the A010 instead. I should also mention that I listened to a Yamamoto A09s (300B) set amp with 94db Living Voice speakers and Lowthers. Very nice sound with on the LV speakers so I Imagine the A09s would be great with the ANEs. I preferred the A010 on the 100db Lowthers because it sounded 'faster' and cleaner, but the A09s was definitely the better sounding amp on the 94db LV speakers IMHO. The less expensive A014, 300B set amp, would have been a more affordable option, too. Not sure If Yamamoto still make them? My local Yamamoto dealer has been unable to get much out of Mr Yamamoto since Covid. He seems to think that Yamamoto were only selling the amps In Japan now? Not sure if this is still the case.

The CA03 phono pre amp has alot of gain and almost too much for the amps, depending on your speakers. I think Yamamoto do a stand alone phono stage without a volume control or line inputs This might be a good option with one of Yamamoto's passive volume controls? Again, depending on your speaker sensitivity.

Sound wise, the CA03 phono stage is lovely but very slightly 'coloured' in a slightly old-fashioned way? So, warmish/full bass, gorgeous midrange and 'golden hued' treble. The SET amps are more neutral sounding. Both the A09s and A08s are a bit warmer in the bass. The A010 is more 'modern' sounding with tight but powerful bass and very 'open' midrange and treble. Using 6A3 tubes gives a slightly warmer presentation and also a bit more 'dynamic' You'd use 6A3s for pop/rock, and VT52 s for jazz/classical. Don't bother with WE VT52s even if you can afford them! WE never made any VT52s but had them made for them by other valve makers. The Hytron VT52s give a lighter / cleaner more 'modern' sound. The Sylvania VT52s give a slightly fuller/warmer sound (lovely).