Sound without the Preamp ?

I removed my tubed preamp and plugged the balanced interconnects directly from the 2 tube monoblocks directly to an Accuphase CD player with volume control. A weird thing happened. The sound got better, more transparent, deeper and tighter base.

This is exactly what should happen going direct if the output stage is good which most dacs are today, more transparent, deeper and tighter base also more detail and better soundstage placement and depth. And "almost" the same will happen with a passive pre, if the input impedance of the poweramp is >10x higher than the output of the passive pre.
As now there’s no distortion/colorations from the active preamp is in the signal path.

Some systems may need to be masked/soften up, with preamp colorations, because they system may have faults elsewhere that need that masking/softening or rounding up in the bass/midbass.

Cheers George

21 years later I learned this .lol....

Joe re ULTIMATE ATTENUATOR. I need to be more careful with Friday posts after the second magarita. The shunt to ground that I referred to is the Ultimate Attenuator from Electronic Visionary Systems. I use the balanced version with my Melos Soloist Triode Monoblocks. I am VERY happy with them. They turned out to be a far better solution than any of the passive preamps I tried. The sound is fantasic without any of the loss I perceived with seperate passive units. I agree with redkiwi that this is probably better with tube amps amps because of the relatively high impedance. The speakers are Dunlavy SC-Vs. Driving my Melos are a Theta Pro GenVa and the new MSB Platinum DAC/Upsampler. I have multiple digital sources. I use Nordost quattro fil as the analog interconnect. With any decent CD I prefer the sound direct in as opposed to going through a passive, a Melos MA333B or a CJ 16ls. There are some CDs where extra tube noise make an abominable CD of a great performance listenable so I am going to keep either my ARc SP-11 or the Melos SHA Maestro ref as an euphonic filter. Downsides recabling for Vinyl but I agree with someone on audiogon who said that is best to listen to either Vinyl or CD but not switch during a listening session. The Balanced Attenuators must be mounted in your power amp. He no longer makes them as part of the connector. Finally, even with the Ultimate Attenuator, these isn't certainty that your DAC or CD and your poweramp will work as a combination without a line stage. Bottom line for me absolutely better than any passive I have tried (which is most available). Better thanclass A tube preamps on a decent recording. Finally, my wife who is as big a music fanatic as I am agrees which is probably the biggest endorsement. One of the reasons that I have so many preamps is we had different tastes in tube preamps even down to the tube sets!

Redkiwi, go to their website. Jeff does it the right way, or no way at all. Unlike every other compromised CD player (including the SCD-1), it uses discrete output devices and the VERY best switched resistor network to control volume. No CD player with volume control that I'm aware of uses such a compromised approach as the Theta integrated DAC that you used as an example.

After "getting into Et's post", I had to try my Sony XA7 (a well regarded CD player or transport) direct into my McCormack amp using the XA7s variable output. Volume control is on the remote. Music quality was so relentlessly detailed and edged that within half an hour it felt like my ears were bleeding; but the tremendous detail was initially captivating. Befroe you guys roast me for this though, I will admit that the probably poor to mediocre variable volume control of the Sony is likely to blame for the poor quality music. It was a big relief to go back to my DAC and SF Line 2 tubed pre-amp. I suspect that good CD players designed to go direct to amp have a very high quality volume control system, eg Carl's CD-50. Any comments about "variable outs"? Craig.

Has anyone used the "Ultimate Attenuator". What are its advantages/disadvantages?

I have had similar experiences with lack of drive from passives, but passives can work very well with tube power amps due to the high input impedence of the typical tube amp.

toMbhcid: In many combinations with a passive preamp what you have heard as to loss of "musical" properties matches my experience. If your CD player or DAC was designed to drive a power amp with an itegrated volume control that's one thing. If the design assumed an active line stage the combo of CD player or DAC, interconnects and power amp(s) may work or not. I tried several combinations before I found one that I liked overall better than a high quality line stage. I now use no preamp and a "shunt to ground" volume control from audiotweakers.com on the balanced inputs of my Melos monoblocks. That set up sounds better than the passsive preamps that I have tried.

What you are saying Carl, sounds right to me, but depends on how the DAC achieves the volume control. For example in the early Theta DS Pres, they used some OP47s in the first analogue stage after the DAC. The OP47s drove both the fixed line out and a preamp stage. The preamp stage had switches, balance pots, a volume pot and then a further line stage using BUF03s. To my ears the sound was seriously degraded between the fixed out and the pre out. In certain cases, using the fixed out into another preamp or even into a passive was superior. The gains from having the pre section in the DAC were minimal to non-existant depending on whether you used a superior preamp to Theta's preamp stage. How do Resolution do it?

Passive preamps have nothing to do with a CD player that has an integrated volume control, as I've said many times before. Such a CD player simply and effectively puts an active linestage inside the chassis of the CD player...just in case some are misunderstanding that.

I have found that replacing the active preamp with a passive / direct does increase the "hi-fi" sounds (imaging,soundstage,noise, etc) but detracts from the "musical" aspects of the performance (dynamics,timbre,pace,rythym,etc.) anyone agree?? I ask why so many listen to an active linestage when a passive is so much less expensive / less complicated??

I too have had great results getting rid of the preamp. I recently upgraded from Meridian 506.24 with Adcom GFP 750 to the Wadia 860x player. I compared the Wadia with and without the preamp, and it was WAY better without. I'm going to spend the extra money saved on better interconnect.

I have a solid state system: Older Proceed DAP connected directly into an Adcom 5802. When I used the Adcom GFP 750 preamp I noticed loss of dynamics and clarity. My DAP has a "hybrid" digital/analog volume control. I have read that controlling the volume in the analog stage is the best for resolution preservation, esp. at low volumes. Any opinions on this?

When I bought my first CD player with a volume control (CAL CL-15) I decided to try it feeding directly into my CJ amp. That was two years ago and I still don't use a pre-amp. It works for me and judging from the previous comments, I'm not alone.

All six previous comments square with my experience, and I found Redkiwi's especially useful. I'm not lucky enough yet to have a CD source with volume control, but hope to get a Wadia 830, 850 or 860 to test against my homemade passive preamp. For those of you with no CD volume control, a high quality passive, which can be homemade--mine is, using dual mono Shallco switches from The Parts Connection, is an option. I also have a CAT SL-1 III with signal path factory-simplified (three or four switches bypassed), and it's not close to as good on CD's as my Shallco passive.

I recently bought a Meridian 518 as a de-jitter device and volume control for my 24-bit-upgraded Meridian 563, and took out my Audible Illusions Mod 3 from the chain. I have 3 superb amps - a Plinius SA 100 MK II with MK III wiring, a CJ Premiere 11a, and a BAT VK 200. I had previously shelved the BAT because it was too soft, but just recently also got a pair of Harmonic Tech 9 speaker cables - which mate gorgeously with the BAT. Anyway, the dynamics and bass of both the Plinius and CJ died, but the BAT, driven with balanced interconnects, became absolutely magical! Full range of dynamics, pinpoint imaging, gobs of detail, and deep bass! Just check you dynamics - it's usually what suffers without a preamp. By the way, my speakers are Proac Response 3.5's. Steve

I had the same experience with my CJ/AI system. And I am using an old Adcom CD player! Also have an MSB DAC, but removing the preamp (and DAC) makes a bigger difference than including the DAC. I would like to know how these DACs with volume controls rate, or these cheap passive attenuators. I don't wan't to spend 3k on a one box CD player at this time.

No, you definitely aren't just hearing things.

I found the same thing removing a top end tub preamp and going directly into my tube monoblocks BUT only after changing my DAC and fiddling with to get the right cables. You were fortunate that it worked on the first try.

No preamp can improve things unless there is something deficient about the output drive capability of your CD player, and only if driving the preamp is easier than driving the power amp. It seems that your Accuphase CD Player drives your amps fine, so why degrade things with imperfect cables, connections, and preamp?

I am currently using my Wadia 27ix/270 combo directly into my monoblocks. I, like you, also have a world-class tube preamp but all the improvements you noted were evident to me also. It seems that, no matter how good the piece, nothing beats "nothing" in the signal path.