[brj]

RDavidson, given that (almost) all of the FW amps are single ended, were you running the Pass amps that way as well, or via the balanced connections?  Running them balanced may very well reduce the noise to which you refer, depending on what elements in the rest of your system are fully differential, among other things.

(I'd love to try some of the FW amps, including the SIT amps and the new F7, but I've built my system to be fully differential from DAC to amp - including even my Pass XVR-1 crossover - so I'd likely be putting the SE amps at a disadvantage.)

[RDavidson]

RDavidson, given that (almost) all of the FW amps are single ended, were you running the Pass amps that way as well, or via the balanced connections?  Running them balanced may very well reduce the noise to which you refer, depending on what elements in the rest of your system are fully differential, among other things.

(I'd love to try some of the FW amps, including the SIT amps and the new F7, but I've built my system to be fully differential from DAC to amp - including even my Pass XVR-1 crossover - so I'd likely be putting the SE amps at a disadvantage.)

The noise had nothing to do with the connection scheme AT ALL. Trust me. I tried fully differential balanced from source all the way to amp. At one time I also had a Bent AVC 1, which if I understand correctly, electrically isolates the amp and source ground from each other by nature of the autoformers. Trying different preamps and connections weren't attempts to get rid of noise. I was just trying different gear and having fun. Note, I also tested for noise by simply turning on my amps (with speakers hooked up) while leaving everything else off. I still got noise (mostly a light buzz / hum).

Keep in mind Pass amps have quite a bit of hardware (MASSIVE power supplies). This is especially true of the .8 series. I don't think it is a coincidence that the XA30.8 was probably the most noisy of all. With speakers with crossover networks and lower sensitivity (like KEF LS50's, which I also owned but not at the time I had the XA30.8 ) noise is less of an issue. Crossover components attenuate some noise and the drivers' themselves will also attenuate some.....which also means they're attenuating what could be important musical content. This brings up another point. Pass amps are direct coupled (ie no coupling caps in the signal path). Other manufacturers put caps in the output stage to attenuate noise and also offer DC protection. Pass doesn't do this, preferring to keep the signal path as clear as possible.

So...nothing is perfect and there are always tradeoffs (both technically and artistically). If you understand the tradeoffs, then they aren't necessarily "problems" as much as they are merely things for careful consideration when choosing your path to listening enjoyment.

Question : Why box yourself into only using fully balanced components? I used to think fully balanced was THE way to go, but later found that I could get as good, if not better sound by keeping things electrically simpler and going single ended. It certainly opened doors to trying some great gear, including more First Watt amps. Give it a try. You may surprise yourself....unless your system is setup in a recording studio or similar environment where EMI and RFI can be a real issue.

[mrvco]

The J2 has easily been the best piece of audio gear that I've purchased since my Omegas.  I've been using a w4s mPre preamp so far, but I'm getting the itch for a different preamp.

I was planning on trying the new Schiit Freya so I could compare passive, ss and tube modes.  However, I'm now considering a used (albeit more expensive) Audio Research LS17 SE Preamp.  Does anyone here have experience matching an ARC pre with First Watt amps and/or Omega Speakers?  The other route I've been considering is a Tortuga LDR Pre for.the remote and a Decware ZSTAGE for the tube magic.

[saygrr]

I once owned the LS-12 and LS-25. I was content for a year or so but the hardness in the macro dynamics was getting to me. Surprisingly it was in the midrange on both units. I have McCormack amps revised by SMC. Had a long discussion with Steve McCormack about my struggles with pre amp/line stages. So I bought an MLD ( McCormack line drive ) SMC revised it to the Platinum + level. The unit is not much to look at but man can it sing. Since then I bought a McCormack TLC  ( Transparent line controller ). This unit is not only nice looking but sings even better than the MLD. Highly recommend you check there web sight and give SMC a call.

If you prefer to have tubes check out K@K Audio. Kevin is coming out with a new line stage.

I bought the K@K Maxxed Out phono stage. It was no contest. Beat my ARC PH3-SE in every way.   

[mrvco]

Thanks, that's very helpful... ARC seems to have a "House Sound" attributed to their gear.  There is an ARC dealer about an hour from here, but I don't remember them actually stocking their gear.  I'd definitely want to demo an ARC pre before paying up for one.  I'll keep an eye open for McCormack preamps.

The Pass Labs X-1 preamp got my attention this morning, so there is no shortage of possibilities to research

[saygrr]

Just to be clear McCormack gear is good value, that can be turned into exceptional gear when revised by SMC. SMC is very serious with their circuits and parts selection. The same is true with K@K Audio . The money goes into the electronics not eye candy hardware unless the customer wants it.
 

[doggie]

Thanks, that's very helpful... ARC seems to have a "House Sound" attributed to their gear.  There is an ARC dealer about an hour from here, but I don't remember them actually stocking their gear.  I'd definitely want to demo an ARC pre before paying up for one.  I'll keep an eye open for McCormack preamps.

The Pass Labs X-1 preamp got my attention this morning, so there is no shortage of possibilities to research

I will add another one to your list. Linear Tube Audio MicroZOTL 2. Sounded wonderful with my SIT2 and my Omegas...and even better now with my LTA-10 EL84 based amp.

[mrvco]

I once owned the LS-12 and LS-25. I was content for a year or so but the hardness in the macro dynamics was getting to me. Surprisingly it was in the midrange on both units. I have McCormack amps revised by SMC. Had a long discussion with Steve McCormack about my struggles with pre amp/line stages. So I bought an MLD ( McCormack line drive ) SMC revised it to the Platinum + level. The unit is not much to look at but man can it sing. Since then I bought a McCormack TLC  ( Transparent line controller ). This unit is not only nice looking but sings even better than the MLD. Highly recommend you check there web sight and give SMC a call.

If you prefer to have tubes check out K@K Audio. Kevin is coming out with a new line stage.

I bought the K@K Maxxed Out phono stage. It was no contest. Beat my ARC PH3-SE in every way.   

saygrr - Do you happen to have any experience with McCormack's LD-2 preamp?  I'm guessing this is the last / latest preamp that was made by McCormack Audio, but there isn't much information floating around on the interwebs about it.

[saygrr]

I am not familiar with the RLD-2. You are correct the RLD-2 came out after the RLD-1 which SMC will work on. When I chose the MLD Steve encouraged me to. They were very excited with this unit after they completed their first one. They were surprised with the results. Then when they did the TLC-1 it turned out even more impressive. I no longer have the MLD. The TLC-1 is unlikely to leave my system. The RLD-1 they work on but have not heard much about it which tells me the MLD and TLC-1 is the direction to go if doing business with SMC. 

[pstrisik]

I will pop this post in here since we are talking about First Watt and Omegas.

I just finished a build of the Pass ACA "Amp Camp Amp".  the diyAudio store has kits for pretty cheap.  They are a pair of all Class A 8w monoblocs with a very simple circuit designed by Nelson Pass.  The kit comes with cheap 19v switching power supplies (like for powering a laptop).  On the build thread, there was talk that upping the DC voltage to 24v was an improvement, and it was even with cheap 24v switchers.  I was enamoured enough with the sound to order a pair of linear, torroidal power supplies in nice metal cases with heat sinks.  Sure enough, even better.  To my suprise, these became keepers rather than a fun experiment.  But I now had four chassis.  So I did a build based on the power supply chassis to accommodate the amp stage (a small board).  Added a heat sink on the top and used poplar wood stained ebony for the modified chassis shape and size. 

I imagine this is a flavor of what First Watt offers and I may have to try the J2 at some point.  For now, I'm really enjoying these.  They are an excellent match with the SAMs.  I am feeding them with the Inspire LP-2 preamp.










.

.......Peter

[roscoe65]

Peter,

We keep running in the same circles.  I've been considering your advice my HT system and am leaning toward using the SAM's are the front channel speakers with RS5-based speakers for the center and surround.  The RS-5 is a little more forgiving of amplification and I would like to be able to use the SAM's for pure music as well as HT.  My Marantz AVR sounds warm and is compatible from a wpc standpoint (it is rated at 50wpc into two channels, which means it is more like a real 30wpc receiver).  But with the SAM's on the front channels I wouldn't mind running a solid state amp off the front preamp outs.  I had just put myself on the email list for when the Amp Camp amps come back in stock.  What I would really want to try is the Aleph J, but it is less of a kit and more of a pair of boards and a design.  I would imagine it would also cost about 3 times what the amp camp would.

R

[tdogzthmn]

Good feedback in this thread!

I've got some Omega's on order and remembered I have a Firstwatt F5 clone sitting in a closet.  I'll try to give it a go at some point Once my speakers arrive.  Hopefully the F5 will be a good pairing with its push-pull Class A design that utilizes JFETs and MOSFETs.  Anyone else have experience with this iteration?

[pstrisik]

Peter,

We keep running in the same circles.  I've been considering your advice my HT system and am leaning toward using the SAM's are the front channel speakers with RS5-based speakers for the center and surround.  The RS-5 is a little more forgiving of amplification and I would like to be able to use the SAM's for pure music as well as HT.  My Marantz AVR sounds warm and is compatible from a wpc standpoint (it is rated at 50wpc into two channels, which means it is more like a real 30wpc receiver).  But with the SAM's on the front channels I wouldn't mind running a solid state amp off the front preamp outs.  I had just put myself on the email list for when the Amp Camp amps come back in stock.  What I would really want to try is the Aleph J, but it is less of a kit and more of a pair of boards and a design.  I would imagine it would also cost about 3 times what the amp camp would.

R

Contrary to what my post might convey, I really don't know what I'm doing electronically.  I followed directions, got some advice on the diy ACA thread and it turned out well.  Might be a touch of luck involved too!

I've looked at some of the other projects including preamps and other amps, but they all look rather daunting to me!

If you do go for the ACA, consider going the 24v route even if with less expensive power supplies.  In fact, I have a pair of inexpensive 24v switching supplies that I would send to you for postage if you were to use them.

I think you are aware that I use a DECWare switch to switch between preamps using the same amp and speakers for HT and music.  If I didn't already have the LP-2, I might not be doing that.  But with a good 2-channel pre on board already, it was preferable to me to add the switch.

[mrvco]

VERY COOL Peter... am I understanding it correctly that the two chassis pictured are what the 24v power supplies came installed in?  The chassis, interior assembly and wood exterior all look positively amazing!

I'll read through the Bride of Zen preamp information and see if I can muster the courage to attempt that project

[RDavidson]

Good feedback in this thread!

I've got some Omega's on order and remembered I have a Firstwatt F5 clone sitting in a closet.  I'll try to give it a go at some point Once my speakers arrive.  Hopefully the F5 will be a good pairing with its push-pull Class A design that utilizes JFETs and MOSFETs.  Anyone else have experience with this iteration?

I owned a First Watt F5 (not a clone) for a couple of months. While it isn't as refined as it's younger brother, the F7 (currently own), I liked it quite a bit. It has a rather spot lit high end which can be fun to listen to and could be a good match for warmer sounding speakers. I wouldn't necessarily say it is a bright sounding amp, but it is a very revealing amp that emphasizes leading edges. Unforgiving is probably the best word to describe the F5. I think Nelson has said as much too. I'd maybe caution pairing the F5 with fast and revealing speakers, like the Omega 3 range. It could work, but may need more consideration in other areas of the playback chain to achieve a balanced / natural sound. It may also depend on the type of music you listen to and the recording quality. If you listen to poorly recorded rock, the F5 with Omega 3's may not work in your favor. But hey, you already have the amp. May as well give it a try.

[tdogzthmn]

I owned a First Watt F5 (not a clone) for a couple of months. While it isn't as refined as it's younger brother, the F7 (currently own), I liked it quite a bit. It has a rather spot lit high end which can be fun to listen to and could be a good match for warmer sounding speakers. I wouldn't necessarily say it is a bright sounding amp, but it is a very revealing amp that emphasizes leading edges. Unforgiving is probably the best word to describe the F5. I think Nelson has said as much too. I'd maybe caution pairing the F5 with fast and revealing speakers, like the Omega 3 range. It could work, but may need more consideration in other areas of the playback chain to achieve a balanced / natural sound. It may also depend on the type of music you listen to and the recording quality. If you listen to poorly recorded rock, the F5 with Omega 3's may not work in your favor. But hey, you already have the amp. May as well give it a try.

Its been a long time since I listening to the amp and I actually bought it originally to use with some AKG K1000 headphones and remember it sounding like nothing I've heard before regarding clarity and detail.  My Omegas are the Junior 8XRS which supposedly share the sound profile of the smaller driver but with more body.  It will be nice to give it a go either way!

[mrvco]

This is more for future reference since I don't believe anyone has had a chance to try this yet, but I'm curious to know how the lower impedance HO speakers sound with the First Watt J2.  While I'm not concerned about the 10W output at 4Ω, the Stereophile review said the J2 didn't measure as well at 4Ω loads and I'm wondering how that manifests itself audibly... if at all w/ the very efficient Omegas.

[RDavidson]

This is more for future reference since I don't believe anyone has had a chance to try this yet, but I'm curious to know how the lower impedance HO speakers sound with the First Watt J2.  While I'm not concerned about the 10W output at 4Ω, the Stereophile review said the J2 didn't measure as well at 4Ω loads and I'm wondering how that manifests itself audibly... if at all w/ the very efficient Omegas.

As with any other case, it likely depends on how loud you want to listen. However, something to note here is that Nelson designed the J2 essentially for single driver speakers. I read this somewhere a long time ago and I'd have to do tons of digging to find where I read this. I'm sure if you emailed Nelson he'd tell you as much. As such, I was not at all surprised that Stereophile found that the amp doesn't like low impedance dips. BUT, this doesn't mean it won't work well for other speakers, and perhaps the HO Omegas would be great match. Though they are 4 ohm, they should be electrically benign for the most part ; Their higher sensitivity largely making up for their lower impedance (compared to their single driver brethren). I fully understand your thinking here. But if you're really unsure about the J2, Nelson has designed other First Watt amps to be more "universal" like the F5 and F7. I think the M2 can probably join that list also, though its sonic signature is a little different from the J2, F5 and F7. Yes, I've had all these amps at one time or another.

[mrvco]

As with any other case, it likely depends on how loud you want to listen. However, something to note here is that Nelson designed the J2 essentially for single driver speakers. I read this somewhere a long time ago and I'd have to do tons of digging to find where I read this. I'm sure if you emailed Nelson he'd tell you as much. As such, I was not at all surprised that Stereophile found that the amp doesn't like low impedance dips. BUT, this doesn't mean it won't work well for other speakers, and perhaps the HO Omegas would be great match. Though they are 4 ohm, they should be electrically benign for the most part ; Their higher sensitivity largely making up for their lower impedance (compared to their single driver brethren). I fully understand your thinking here. But if you're really unsure about the J2, Nelson has designed other First Watt amps to be more "universal" like the F5 and F7. I think the M2 can probably join that list also, though its sonic signature is a little different from the J2, F5 and F7. Yes, I've had all these amps at one time or another.

Thanks, I've heard the same thing regarding the design goal of the J2.  I'm pretty good about keeping listening level peaks no higher than 91 or 92 db from my listening positioning.  Anything louder than that and I can feel it working in a noticeably unpleasant way on my ears (and not in a way that it sounds bad on any level or that I'm overdriving the amp or speakers).  The good news is that if the J2 wasn't ideal with the HOs, the J2 (and all the FW amps seemingly) don't sit very long looking for a buyer.

[RDavidson]

Thanks, I've heard the same thing regarding the design goal of the J2.  I'm pretty good about keeping listening level peaks no higher than 91 or 92 db from my listening positioning.  Anything louder than that and I can feel it working in a noticeably unpleasant way on my ears.  The good news is that if the J2 wasn't ideal with the HOs, the J2 (and all the FW amps seemingly) don't sit very long looking for a buyer.

Though I currently own the F7, I'm very fond of the J2. I sometimes have thoughts of getting one again. The F7 is a bit more balanced across the board and has a bigger presentation, but the J2 has a sense of speed and inner glow that make it quite fun and addictive to listen to in its own way. Both sound completely natural, and are very very highly resolving, but present the music a bit differently.....providing their own "interpretations" of the recorded signal. If the J2 doesn't work out, I'm pretty confident the F7 would be the best alternative from First Watt for you.