2. amps-preamps
  3. 131753-4121

PLEASE match Advice Pass Labs X350.5 (20k) to Hovland HP-100 (2500ohms) Miss-match ???

GUYS / GALS NEED YOUR HELP PLEASE!

A friend said this preamp is outstanding and will sound great with Pass Labs amps and to not get caught up in the specs but the measurements say different.

Pass Labs X350.5 amplifier with input Impedance 30k ohms Balanced or 20k ohms Single ended* 
(*source Pass Labs Manual)  

Hovland HP-100 source impedance 2500ohms* 
(*source Stereophile) 

Guys / Gals, can I used my Pass Labs X350.5 amp with Hovland HP-100 preamp? Has anyone used Pass amps with Hovland pre's. I will be using Magico S5 Speakers and Bricasti M1SE DAC but want it to sound the best it can. Should I just stick with the Aesthetix Calypso pre I was leaning toward before my gut said to go for the Hovland HP-100

Hovland HP-100 Preamplifier: * Output impedance: approximately 2500 ohms or according to Atkinson, Hovland HP-100 (2500ohms) its source impedance was high at 2.4k ohms, rising to 4.3k ohms at 20Hz. The partnering power amplifier would best have an input impedance of at least 47k ohms if the bass is not to sound lean*. The Pass Labs doesn't meet the x10 requirement it is supposed to but it is sort of close when looking at it. What do you guys think? I am not sure what to do but you guys will know what to do?

Stereophile: Its input impedance was a usefully high 100k ohms in the midrange and bass, with just a small reduction to a still-high 86k ohms at 20kHz. Despite the claim that the HP-100 uses a cathode follower output stage, its source impedance was high at 2.4k ohms, rising to 4.3k ohms at 20Hz. The partnering power amplifier would best have an input impedance of at least 47k ohms if the bass is not to sound lean.

Read more at https://www.stereophile.com/content/hovland-hp-100-preamplifier-measurements#YZXZfGLbbL2COkLR.99 https://www.stereophile.com/content/hovland-hp-100-preamplifier-measurements#YZXZfGLbbL2COkLR.99
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jahatl513
119 posts
 
I had this same burning question. Nelson Pass answered it for me himself. He said the Conrad Johnson single ended triode was an excellent fit for his amps and highly recommended the pairing. Look on the DIY sites where he frequents or email him yourself.
I was skeptical as well and borrowed a Pass XP10. Lovely preamp with many things I like about it. The really real was that my CJ Pre’s and I have a few; all attenuated better; sounded best with my CJ Premier 16LS2 and my CJ ET-5. Nelson was correct.
kw6
692 posts
 
I can agree with jahatl! Get a CJ ET-7se and be done with it. One of the top 5 preamps in the world today. GAT 2 being the other one. Cj has the prat thing going for it which makes other preamps sound less analog!
kw6
692 posts
 
If your speaker is neutral u dont need all tubes. Cj pre with pass amp great combo. If you get tube pre and tube amp. You will lose prat & fine detail. Nuances! I had set before sounds nice but loss of fine detail and bass dynamics. But to be fair my speakers weren't really efficient.
analogluvr
859 posts
 
 For the most part I don’t necessarily think it’s about tube and solid state. I totally disagree that you lose fine nuances with Tubes in fact I would tend to say it’s the opposite. One thing I have never heard solid-state do as well as Tubes is the holographic imaging thing. 
 So even though in my first sentence I say it’s not about one versus the other then I go on to say that I prefer Tubes LOL.Maybe I just haven’t heard the right solid-state stuff although I’ve heard most of it.
One thing I had a question about is earlier on in this thread someone mentioned to stay away from a cathode follower because of rising impedance Or something like that. My understanding was that a cathode follower is there to make the unit able to drive the next stage without mismatch problems? Is there something I’m missing?
kw6
692 posts
 
I agree analogluvr! I was trying not to piss off tube afficianos! 😁

That's why I love cj only one tube rest is with good parts and volume control. I had the highly touted LTA MZ2. It sounded nice, did layering was airy & somewhat rounded. But lacked prat, transient bite and fine detail which gave CJ an edge in dimensionality. Eg. Snare kit being hit sounded more realistic projecting out 360 degs.
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