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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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fsmithjack OP
712 posts
 
Thanks Jond - that's very good advice! I've been wanting a Pre for a while but you are right. I didn't really like my Bricasti direct with my Rethm's but I made some other changes that had nothing do with a pre and now after a month or so I really do like it direct now. Well that was before the speaker change :) 

 I run my Bricasti Dac via USB and picked up the new Uptone Audio ISO Regen with its matching capacitor charged / driving LPS-1 Power Suppy and then I was using my Pass Labs X350.5 single ended but I wasn't using the XLR jumpers. Nelson told me the jumpers on this amp makes a huge difference and send me a pair. It made a huge difference' I was psyched! These two changes and some mental audio adjustment time and now I love the Bricasti direct so investing time is a very good idea. I am wicked impatient though... lol 

I've done ok though. I was able to hold off on the Pre until I got my new speakers like everyone told me to do which for me was good.

Also, I sold all my SET tube gear and my analog rig and cables and carts so I wanted to put that money back into audio products before it vanished into bills, life, etc. Atleast if I get something I don't love I can flip it - if I spend the money on something else then poof it's gone forever... lol 

thanks for the sound advice! 
timlub
2,039 posts
 
Here is something a bit different to consider: 
https://forum.audiogon.com/discussions/anyone-heard-of-t-a-theory-and-application
and another review:  http://www.theabsolutesound.com/articles/one-of-the-best-preamps-youve-never-heard/


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jmcgrogan2
6,346 posts
 
BAT VK-51SE
BAT VK-32SE
CJ ET3SE
CJ CT-6

Any thoughts - think I'm leaning toward the BAT VK-32SE

I called BAT they said its the sweetest of the BATS and have same bass and dynamics as the others. The 51SE a little more neutral but the Magico's seem to be looking for a bit of sweetening.

I've owned the VK-51SE, VK-50SE, VK-31SE, and had the VK-32SE in my home for a one week audition.

I would agree that the VK-32SE is the sweetest sounding preamp of the BAT bunch, but it did NOT have the bass and dynamics of the VK-51SE.
Unfortunately in life, one can't have it all. I preferred the VK-51SE in my system.

In the end, I sent the VK-32SE back to the dealer, too sweet for my tastes.
I wound up buying an ARC Ref 3 instead. Now this was about 9 years ago.

I've also owned a CJ Premier LS 16 mk II, which was also a sweet sounding tube preamp. A bit more refined sounding than the VK-32SE, but the VK-32SE did have more power and dynamics than the CJ.

I would think if you are looking for sweetness, either CJ preamp, or the VK-32SE would be best suited for you.

The VK-51SE has more dynamics and power than any other preamp on your list, and though it may sound warm compared to ARC or VAC preamps, it is not as warm as the other 3 preamps on your list.
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fsmithjack OP
712 posts
 
Jmcgrogan2 - thank you so much - super helpful - I'm actually pretty bummed - should say super bummed - got my Magico S5 set up and I mean everyone says how incredible they are - I have a first rate source - Bricasti M1SE - first rate amp - Pass Labs X350.5 which is known to be a pretty warm amp - HiDiamond D8 Speaker Cables which are not Nordost Oden but very nice copper cables and quite compitant, Verestarr Grand Illusion Signature IC's which are also very nice and even a bit warm and these Magico's are burning a whole right through my head like a lazier beam. I've been setting them up and measuring and tweaking and they are giving me a royal head ache? How can this be? These are top rate speakers? They make me want to buy a Cary preamp and CJ tube amp and get Cardas Golden Cross Cable Full Loom? Which I can't do and I'm sure would sound like crap? Even my wife said these don't sound as nice as your other speakers? Any advice? Maybe my bran needs to adjust but there is going to be some serious adjustment- my last speakers were total opposite of laid back - they were ultra revealing but I wasn't expecting this? Bummed to the extream but also hoping a tube pre and maybe a cable change can get these to settle down?? Maybe need to be driven a while also? Just back from Magico and had some service so maybe some new parts or something needs to break in?? 


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jmcgrogan2
6,346 posts
 
Well Magico speakers have a reputation for being very revealing speakers.
I am familiar with your amp, and yes it is known to be a warmer sounding amp.
I am not familiar with your source though. Perhaps you may be better off with a tubed DAC, like a Lampizator.

Then again, maybe there is nothing you can do to ever make the Magico's work for you. You are at a fork in the road. Should you try a warm tube preamp and warmer cables to help tame the Magico highs?
Or just cut bait and sell the S5's now?

I wouldn't make an impulsive decision, think about it for a while.
A Cary/CJ preamp and some Purist Audio or Kubala Sosna cables could save the S5's. However, if they do not, then you may need to go further and try a tubed DAC too.

I have a friend who loves his S5 Mk II's. He is using them with Vitus CDP and electronics, and Jorma Prime cables.

Good luck,
John
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