2. amps-preamps
  3. 1337442980

Preamp possibles for system...

I am currently using a Belles 21A auricap but have been itching to try something else for possible system improvements. The amp is a T-hold S/500 ll with an Arcam CD23 and Polk SDA-2's with RDO-194 tweets. All IC's/PC's are Morrow Level 3/4. My 22'x35' listening environment is slightly harsh with wood floors and a fair amount of glass. Musical taste is quite varied at moderate volumes.

In general, I feel the base or low level frequencies are a bit forward but not crisply defined. Also the high frquencies seem somewhat constrained or maybe rolling off early...using others terminology I have read. Almost as if the singers are behind the band. Not always, but on enough recording's I notice it.

My previous amp was a Nak 7. Everything else staying the same, I recently switched to the T-hold S/500. I literally would have wrote an exact opposit review of the systems traits critiquing it with the Nak. I was certainly surprised...in a VERY good way.

I have read that the T-hold amps liked certain pre's. Here is a list I have gleaned from some research. I have not seen all of these available, so some maybe out of the question. I would be gratefull for any input to try and target my continued refinement.

Sonic Frontiers line 3
Aestetic Calypso
Audio research LS25 mk1 or 2
Modwright 9.0se
Klyne 7

mlo97
mlo97 OP
31 posts
 
I would like to extend "Thanks" to everyone who took the time to respond. The info has given me both something to ponder for a sense of system direction along with items to keep an eye for and contiune research on.

Bigshutterbug...I am using the original Mullard's currently. One of my reservation with the 21A has been comments associated with it not matching the Threshold impedences well. It truly tamed my previous Nak 7 compared to a Rotel pre I had used originally. I have been using it very happily until recently adding more and varied music and also moving into a larger home.
bigshutterbug
381 posts
 
Ml097;
You might want to try replacing the Mullards with a pair of Amperex Holland 1960's 12AU7's. The Mullards are warm and rich 12AU7s with sweet highs, where the Amperex 12AU7s
are faster, more lively and energetic, with more extended highs and a tighter, more defined bass. Give some a try...
mlo97 OP
31 posts
 
Thought I would post an update. I was mistaken about the Belles preamp tubes being Mallards. Turns out they were RCA 5814A's. I installed the oem equipped Mallards for a oem base-line test. Heading Dayglow's advice I also purchased a Bryston BCD-1 in order directly compare with the former Arcam.

With only a very short time of listening the changes in tubes and the cdp are quite dramatic. Music is certainly brighter and appears larger or more forward. Maybe even too much for my taste and/or listening environment. Lower frequency's and or/bass do seem slightly crisper. I am hearing things like string squeaks and low frequency tones clearly that were barely noticeable before. I feel it was a good direction of funds and will give me a decent standard to experiment with via different tubes and some room changes.

Hearing what I do know is sort-of taking my attention off the preamp and maybe directing it to the speakers...if my desires were to soften things up. Does that makes sense?
unsound
7,329 posts
 
As I typically do, I suggest finalizing your speaker choice before doing anything else. The speaker/room combination will have more total effect than anything else.
With that said, re: preamps with the Threshold S/500 Series II. Many of your choices appear to have balanced outputs, something your Threshold series amp doesn't accommodate. Keep in mind that adding true differential balanced operation to gear is not an inexpensive consideration. If your intent on keeping your amp (and a very fine amp it is) then perhaps you might want to partner it with a pre that might have used the extra costs otherwise spent on true differential balanced operation on other parameters. That is not to say that a balanced pre should automatically be disqualified because you'll be using it's single ended output, or that balanced operations doesn't have it's virtues.
Again, I suggest you reconsider your speakers before doing anything else.
mlo97 OP
31 posts
 
Thank you for your input Unsound. My budget keeps me having to research and watch the used market to build a system I know I would otherwise not be able to own. I am very fond of the amp as I was the Polk speakers though I completely understand thier place and time in the marketplace. My current listening sessions seem to be reflecting new shortcomings in the speakers from either design or thier age. I hear more detail than ever but the general tone and low frequency quality is not not where I would like it.

Unsound, could elaborate on what perameters would be usefull in a single ended optioned preamp selection?

My listening area is quite large. It encompasses a great room concept floorplan with the speakers being located nearly against the front wall. A couple speakers I have been focused on are the Dunlavy Contata's or Legacy classics/focus. Seems they are capeable of filling a large area and may be more leniant than many at being located near the front wall with thier woofer design. The prices I see would be my upper price threshold but realize the importance to the system.

More to discover