Audio Horizons TP 2.0 Preamplifier


Anyone famaliar with the manufacturer,and in particular
this pre amp.The credentials and testimonials seem
impressive.The advertised 10 day audition is appealing.
markwatkiss
I have heard the TA 18 amp. It is an EL34 SET. It is excellent. The 845 SET amp is still being tested by Joseph.
wanted to update folks on some mods that i did to my unit which changed the character of the player:

1) V-caps for coupling caps (biggest improvement you can make for clarity, dynamics)
2) signal wiring harness upgrade: the silver-plated copper thats stock has a forwardness in the upper midrange / lower treble i found objectionable. replacing it with mundorf silver/gold ($8 / ft. god i'm dumb) helped town that down while making things more liquid and listenable
3) replacing all DC wiring (stock is 24ga, which does limit dynamcis when compared to the 18ga vampire wire i put in)
4) replacing RCA jacks w/ Eichmanss...really one of the best jacks out there, again removing upper midrange glare (slightly). if nothing else, replace the output RCAs (inputs are VERY tough to do)

(of course, unit responds very well to vibration damping & mass loading)

if you're very adept at DIY, you can do these in a day. if you dont feel comfortable removing the volume pot & drilling new holes in chassis (required), best send it to Joseph as i believe he's incorporating these mods as well (i've gone back & forth with him on these things).

minor attention to detail makes a bargain player into something competitive with $14k players (i know, i A/B'd them and it was a "pick what you prefer" outcome rather than "this is clearly better than that").

amazing. just amazing.
Mark,
Since you are the one who started this thread, I think that you should be the first to try the new amp. Only fair. (o:
Sherod,just wanted to make sure you're still reading this thread.Best of the New Year.
Let me make add a comment about the TA 18. We know that Joseph delivers products that are balanced and uncolored in their presentation. This amplifier has all of the excellent performance qualities we expect from Audio Horizons products. It is subtle, detailed, natural, lively. I found the most striking quality of this amplifier to be the way it handles the frequency extremes. I am amazed by its full range performance.

In this thread we devoted hundreds of posts in which we described the qualities of the TP 2.X preamplifier. I believe this amplifier is every bit as excellent as the TP 2.X is excellent. I'm interested to see how other audiophiles receive it.
Holy Cow this is a HUGE thread! I've come across this pre from a recommendation from someone who doesn't own it but recommend that I take a look. It seems to have everything that I need. Two Balanced outputs, remote and RCA inputs.

So the bazillion dollar question. How does it sound? Are you early owners still happy with it?
Very very happy still with service, reliability, and sound.
But am replacing mine due to WSF wanting simpler equipment, with the $11,800 Ayon CD5's (Transport,DAC, and preamp all in one box so she can operate easily)- only thing I found that satisfied as much as the AH. Disclosure - my AH is for sale.
I have purchased a used 2.1nbr c/w clarity caps furutech IEC and HI-FI tuning fuses, and was hoping some owners may pipe in with a little help. I am experiencing some feedback issues...with no music playing, that and everytime I touch the case or anyhting like that, I hear it through my speakers. The tubes currently have some hiss in the background, am I experiencing a tube on its way home? Has anyone had this experience?

I am currently using the RCA's.

My other pre is an Audible Illusions L1 and I have heard nothing like this, hence my curiosity.

Thanks
I had I think a similar issue with my 2.1 and it turned out to be tube microphonics. Using Herbies tube dampers eliminated it by dulled the sound, floating the circuit board helped a bit, also you can try very gently bending the pins out just a bit on the offending tube to get a tighter connection. You can tell which tube is trouble by pulling off the top and while the unit is powered up and connected to speakers, gently tapping the tubes with a pencil eraser. You will hear if one tube is particularly microphonic.
The best solution however that I found that completely eliminated all noise and made the unit totally silent was to replace the tubes with other 6922's. I found Seimens 1960's cca's to be amazing in the unit, but also cheaper Amperex PQ's etc provide wonderful sound. Don't give up- it is a wonderful preamp and this should be able to be fixed easily. You can also talk to Victor or Joseph at AH and they will do everything in their power to help you.
Thank you very much for your help. I thought it was a tube, but best to ask. When music is playing it sounds remarkable, it sounds like everything I hoped my stereo would one day be.

One last question, the unit I have purchased has the remote on/off, do you turn it off completely on the chassis or use the remote? My AI standby always had limited current going to the tubes to ease start up.

Thank you again.
I did not have a remote and turned it all the way off until I went to use it. It has a soft start up to be gentle on tubes. My tubes showed very little use on my tube tester after 3 years of use with the cca's at about 2 hours per day. I would email AH on this question.
Glad you like the sound, it is indeed wonderful.
Folks, I just purchased a AH 2.1nbr preamp and have a few questions about it...

It has basic EH tubes in it, and I would like to upgrade those to a better quality tube. Any recommendations for a first roll? I'd prefer to no be purchasing $200/tube valves for this. Maybe some mullards? Actually, this thread is so large that I know that there has been some discussion about what the various tubes impart to the sound; I'm wondering if there is a good summary somewhwere.

I think someone long the way may have made a mod or two... the fuse housing to the right of the IEC outlet is not hooked up. I'd prefer to have some protection for the preamp to keep it from burning up if there is a problem. There is a fuse on the board nearest to the IES socket, but I am speculating that it is a secondary fuse. Can someone provide me with a photo or two showing how the input power fuse is supposed to be hooked up? I'll get it wired up from there.

The main ON/OFF switch on the preamp was damaged in shipping, and I need to replace it. Joseph says it'll be $25, but he is out of the country for the next month. Does anyone know exactly what the switch part number (manufacturer, etc.) is? If it's nothing special, I'll find it from another supplier and wire that up as well. Id rather not wait for Joseph to return, although I am able to get the switch to work (for now, not sure for how long, though).

Lastly, there is a bit more hiss with the preamp in the system than I had expected based on comments I have seen, so I'm wondering if this is somewhat dependant on the tubes? I don't believe the hiss is volume dependant, but it does change as the preamp goes through it's warmup. It's currently hooked up via RCA, but I'll eventually get a balanced-capable amp, which hopefully will reduce this effect if nothing else will.

Thanks,

---Michael
I strongly preferred the early 60;s Siemans cca's. But the cheaper Amprex White Label PQ's were also good, abit wetter and less controlled. Hiss level may vary with tubes. Unit should be very quiet, just a tiny bit with your ear right up to the tweeters.
hmmm...

I am having problems with the left channel popping and increased hiss on that side. I think there is a problem with this preamp. I reversed the tubes to see if it was them, and the problem stayed on the left, so I suspect there is a problem in the preamp somewhere...

This explains the higher hiss than I was expecting I think. It's really unfortunate because it sounds great when it's working fine, but I think this one has problems somewhere...

I'll talk to the seller and see what my options are.

---Michael
Michael
If you want to keep, and seller is not cooperating, send it back to Joseph Chow who designed it at AH and he will make it right.
This thread suddenly went dead for over a year now. I'm curious what everyone is doing now. I had a lower abdomen hernia surgery in Nov. 2010 and went into a slight depression and lost interest in my music system. I shut the system down for over two years but recently got back my interest and am enjoying the music once again. Anyone upgrade to the new 2.3 version/s? I'm still enjoying my original 2.0. I have come back to using the original Hovlands in the ouputs, mainly due to a tweeter cap change in my speakers that greatly changed the overall sound for the better. I hope everyone is doing well.
Sherod, try those JB JFX caps in your pre and you will smile. Glad you are doing better.
Thanks, Grannyring. I'm still trying to get the full measure of these JB JFX caps in a speaker crossover. I've got an extra pair for future projects.
Sherod welcome back and glad to hear you are feeling better. Though I moved to Ayon I still have great respect of AH sound and support and would love to hear the 2.3 myself.
Thanks, Gammajo. I hope you are doing well also. I hear our friend Pat paid you a visit recently. He told me he really enjoyed the visit. My daughter lives in Fayettevile. I'm hoping to visit her sometime this Fall.
Thanks, Gammajo. I appreciate the open invitation. Let's see how things go for me until Fall.
Sherod , glad to hear your up to par.
Go play your White Christmas by the Drifter's.That should get your feet tapping.
You've got a good memory, Goldeneraguy. Good idea...every time I play the Drifters White Christmas, it does put me in a good mood.
I recently purchased the TP 2.3 preamp. I had some Siemens Cca ready to roll. I was surprised with the results. The synergy was not working with my system. I have had good success with Amperex 6922 and Philips SQ -- rotating between 1 to 3 and 2 to 4 -- while I await the delivery of other tubes. The TP 2.3 is starting to sound like the great amp others have written about on this thread.

Regarding tube rolling, I have read of success with Amperex PQ White Labels. I have been in touch with Joseph Chow who has suggested I try Telefunken (I assume E88CC) in 1 and 3 and Mullard CV2492 (preferred) or Amperex (not yet specified) on 2 and 4. Does anyone have experience with this? Thanks for any helpful suggestions.
When I owned my AH I found that maybe one in 5 sets of Cca's even from reputable sources sounded amazing and the rest just OK. These best sets of Cca's beat everything else, but the rest of the Cc'a for me were beat out by Amperex White labels. Hope this helps - its a great preamp!
Gammajo,

That's interesting. I tried a pair of Siemens Cca and they did not work for me in positions 1 and 3. I am now using a pair of Philips SQ in positions 1 and 3 and they are very good. I have other tubes coming to compare.
I did a lot of research over the years on the various Siemens E88cc tubes. The famous Cca and E88cc from Siemens were made identically. The only difference was that the Cca were hand selected for low noise for the German postal service. Otherwise, they both sound identical. The secret is to find either one made from 1959-1965. The best ones have a dimpled getter support( although some have no dimples) with codes etched on the glass or plate of support of three lines, reading vertically of A12, A13, A14, and A15. The A16 and A17 don't sound as good. I read this from users on the Tube Asylum and have proven it to myself. It is also important to find one of these models that has high emission rate with low, noise, zero microphonics, and no shorts or emission leaks. I spent a lot of money for an early pair of Siemens Cca a few years ago and they sounded terrible because of noise and emission leaks. I bought an inexpensive tube tester to test all tubes that I buy to make sure that they meet the seller's ad specs. Also, beware of fake Siemens tubes. A good eye can spot these fakes. In any event, once you find the right Siemens E88cc, you will have many years of wonderful music before they lose their emission strength and you have to buy another pair or more. I have a quad in my back-up that should hold me until I'm playing the trumpet in Heaven.
Sherod
That trumpet will be a relief from all that harp music, especially if you know some jazz:)
Joe,
I'm guessing that Heaven, with all the great musicians who have gone there already, is filled with some great jazz groups, orchestras, symphonies, etc. One can only imagine the kind of music that is going on up there.
Anyone have experience with Amperex, Telefunken, Mullard or other brands with the TP 2.3?
Sabai...does your 2.3 come with Joseph's new tubed power supply. If not it is worth contacting him about it. It made a huge improvement in my unit. Much improved staging and dimensionality. It is very organic sounding now where it had been a touch on the clinical side previously. IMO well worth the 1k for this mod.
Wow...I didn't know that Joseph now offered a tube power supply for the preamp. I might have to look into this. Has anyone tried Joseph's new Reference Platinum "More than a fuse"? I recently replaced a silver Hifi-tuning fuse with this new AH fuse in my TP 2.0n and the sound improved immensely...well worth the price. Joseph offers a couple of discounts to current AH preamp owners and if you post an impression of the fuse.
Scifi,

Is this an external power supply? I have the 2.3 with all the trimmings that are advertised on Joseph's site but I don't recall reading about this specifically.

Sherod,

What were the improvements with this new fuse?
Sherod,

Yes I have the new fuse as well. Nice subtle improvement for sure. I also sprung for two for my 3.1 DAC.

I would contact Victor if you do have interest in the tubed power supply. He can most certainly give you quite a bit of information about its merits. I have had mine since last March and it has really transformed this preamp from very good to outstanding.
Sabai,

No it is internal and replaces the current internal power supply which is on the left side of the unit as you face the front. It uses one tube. It really made a very special improvement in the unit as I wrote about in a previous post.

Contact Victor Comerchero, spokesperson for AH, for more details. He will not steer you wrong.

I don't think it is advertised as an upgrade on his website, but I learned about it from Victor in email conversation.
Sabai,
You can read a brief comment I made on the new fuse along with other user's comments.

http://app.audiogon.com/listings/tweaks-audiohorizons-platinum-reference-more-than-a-fuse-2013-11-23-accessories-95670
I was wondering if anyone received an owner's manual with their AH preamp( any version). I don't recall getting one and was lately wishing that there was one. I would like to get a schematic of my TP 2.0 to look it over. I haven't talked with Joseph or Victor yet...I thought I'd get current owner's comments first. I didn't see one available on their web site to download.
Sherod,

I have a rudimentary users manual when my unit was a 2.0 but no schematic in that info. Another omission in the early manuals is the fact that the preamp inverts polarity. Make sure all who use this preamp switch positive and negative speaker cables EITHER at the amp end or speaker end (not both) to get the correct phasing.
Sherod and Scifi,

I have contacted Joseph Chow about the tubed power supply grade. I will report back here -- hoping to have a positive outcome soon.
Sherod and Scifi,

Sorry about the typos. My previous post should have read:

I have contacted Joseph Chow about the tube power supply upgrade. I will report back here -- hoping to have a positive outcome soon.
Just a note: I recently emailed Joseph and didn't get a response, so I forwarded the email to Victor. Victor told me that Joseph was extremely busy lately, hence his delay in responding. You might get faster response if you email Victor: vcomerchero@sbcglobal.net