Adding a preamp

[Nelson de Leon]

here's my current set-up:

Sources:
Cambridge 740C
Mede8er NMT

Amp:
SE 2A3 power amp w/ passive attenuator

Speakers:
Klipsch RB-81

As you can see, i still don't have a preamp. A friend of mine also had a similar set-up but when he fitted in a preamp, his imaging and stage significantly improved. I know for a fact that a preamp is primarily for matching the input of the source and input of the power amp but how does it improve the stage and image? How does the increased voltage input on the power amp help?

[JoeyGS]

I would recommend the Aikido if you are looking for a tubed preamp.

[Nelson de Leon]

I would recommend the Aikido if you are looking for a tubed preamp.

By Jojod? Already have one in the making. Just need to verify a few questions of mine. Thanks Joey!

[brady]

Hi Nelson ... IMO if you have sufficient gain, no need for pre-amp. A pre-amp will just insert another stage (or stages) to your audio chain.

[fld]

I personally would prefer to add a pre-amp to the system rather than controlling direct from either a cd player or phono stage.
It adds another stage but adds sonic character which for me is better than just straight to the amp.

[Gino]

Nelson, you'll know soon enough. You have a preamp on the way and it is pretty much a done deal. I normally ask before I buy anything. Just keep us posted when the system is up.

How good is the sound quality of the Mede8er?

[mullard88]

Hi Nelson,

I do not know why but it seems like for most digital front end, a preamp makes the sound easier on the ears. I have experimented with connecting two preamps in series and to my ears, this improves the sound even more.

[ojof00l]

heto na,eto na,eto na...doobidoobidoobidoobidooo kung kelan parating na JP preamp tsaka ka nag-post hehehe. parinig naman, balita, holy grail of audio daw ang setup mo

[Nelson de Leon]

Hi Nelson ... IMO if you have sufficient gain, no need for pre-amp. A pre-amp will just insert another stage (or stages) to your audio chain.

Not much heaadroom for a 2A3 3 watter hence, not so sufficient gain though a bit beyond normal listening levels na. I'm feeding it with 2.2 volts from the cdp.

Nelson, you'll know soon enough. You have a preamp on the way and it is pretty much a done deal. I normally ask before I buy anything. Just keep us posted when the system is up.

How good is the sound quality of the Mede8er?

I cannot tell the analog sound of the mede8er cuz i only use it to play the digital files from my external hdd. it's connected sa cambridge 740c digital input via coax so in a way, cambridge sounding din. I didn't dare hook up the mede8er via rca/analog cuz surely, i will get dissapointed. System is up and well naman w/o preamp. Tubey british sound.

I personally would prefer to add a pre-amp to the system rather than controlling direct from either a cd player or phono stage.
It adds another stage but adds sonic character which for me is better than just straight to the amp.

Yes, it will definitely add another tube sound character to my system but i was afraid that the transparency of my system might suffer.

heto na,eto na,eto na...doobidoobidoobidoobidooo kung kelan parating na JP preamp tsaka ka nag-post hehehe. parinig naman, balita, holy grail of audio daw ang setup mo

Haha! So not true. malakas lang mang-asar sila.

[tuscany]

I had Rene (Hypertriode) change the attenuator of my tube preamp to a Dact and provide a switch that would bypass the active stage of the tube preamp, converting it into a passive attenuator only. I find it more transparent and able to catch the details of the recording better. Instruments also sound more natural and relaxed without losing dynamics. Not to mention that it has reduced my electricity bill (I assume) as I don't have to power on the preamp anymore.

Of course this will probably apply only to my system as the passive attenuator is more system dependent than an active stage.

[Nelson de Leon]

I had Rene (Hypertriode) change the attenuator of my tube preamp to a Dact and provide a switch that would bypass the active stage of the tube preamp, converting it into a passive attenuator only. I find it more transparent and able to catch the details of the recording better. Instruments also sound more natural and relaxed without losing dynamics. Not to mention that it has reduced my electricity bill (I assume) as I don't have to power on the preamp anymore.

Of course this will probably apply only to my system as the passive attenuator is more system dependent than an active stage.

This was really my initial plan for my power amp. though i'm considering adding a bypass switch with the proper resistor value to my power amp when i get my preamp.



Let me rephrase my first question, how does adding a preamp (or higher voltage input for the power amp) improve the image and stage?

[zenaudio]

I personally would prefer to add a pre-amp to the system rather than controlling direct from either a cd player or phono stage.
It adds another stage but adds sonic character which for me is better than just straight to the amp.

This is probably the most common reason for adding a preamp.
Having a pre-amp also adds gain before the power amp therefore adding some "headroom" for the power amp/system?

[Nelson de Leon]

Hence the added gain give better image...?

[brady]

Hi Nelson. 2.2vrms from your source is plenty. of course, depende how your amp is planned.

I would define "gain" or the more comprehensive term "gain distribution" (since you distribute this in all the stages - from your op-amp in a CD player or step up in a phone stage all the way to your 2A3) as the voltage increase required by the amp, given a certain voltage, to drive your final stage. "headroom" - I think - is the peaks/transients that the amp can muster before clipping.

I usually aim for a gain where the volume pot is around 3 or 4 o clock in normal listening levels.

at any rate, your best judge will be your own ears (your built-in analog to digital converter).

[brady]

re amps/gain/head room

i remember a few years ago comparing a US$6k 300B integrated (transformer-6C6-cap couple-300B) and a cheapo diy (5687-cap-5687-dc-45) ... 1.5vrms from CDP into horns. The 300 amp, which was supposed to be 4 times more powerful, sounded like a dengue patient suffering from asthma.

[Nelson de Leon]

Hi brady. I "feel" you.

By adding more gain before the power amp, i have a few additional headroom thereby giving more dynamics towards my speakers.

Correct me if i'm wrong...

[brady]

Hi Nelson. This is just an opinion. Gain (either right at the source, or via a pre-amp, or adjusting values in the voltage amp) is just the voltage gain.

Headroom, otoh, and therefore, dynamics, is the ability of the amp to "go the extra mile" before it clips (and distorts the original signal). These are the quick and rapid stabs at LOUD and SOFT. This is determined by operating points of your final stage, and the driver's ability to deliver both voltage and current to the final stage. In my earlier example of an illogical amp, a 1M ohm driver capable of a wimpy 1mA is hardly a choice to drive a 300B.

[egay]

...As you can see, i still don't have a preamp. A friend of mine also had a similar set-up but when he fitted in a preamp, his imaging and stage significantly improved. I know for a fact that a preamp is primarily for matching the input of the source and input of the power amp but how does it improve the stage and image? How does the increased voltage input on the power amp help?

hi nelson,
i am not a techie so i looked for some sites for you and here is a simplified explanation which also helped me understand how a preamp ties everything together to sound how they sound
http://www.ovnilab.com/articles/preamp.shtml

my opinion:
for more than 10 years, after initially discarding my analog for digital, i drove my amps using my Wadia as the driver [1] because i only have 1 source so i don't need a preamp, [2] because the Wadia sounds 'just right' for me then, & [3] i thought of a preamp as just 'another' stage to ruin an otherwise 'pure' SQ from the source.

however, after trying out preamps, i changed my impression and now believe that a preamp is the heart of the system.

yes, there are still those who believe & would probably die with their belief that they don't need a preamp. fine.

but i am one who belive we need one BUT choose with care.

i have done passive ones with very limited inputs because i find too many inputs a waste of money; then i found a preamp that really fits my need - balanced, 2 inputs [xlr & rca], and looks 'just right' - the missing "link" for me.

listen & believe.

.e.

[Nelson de Leon]

Got it. Thanks Egay. Impedance matched = better gain/volume = added a little headroom for dynamics = better stage.

[zitric]

sir, newbie here, pa add lang po kung pwede sir nelson...

how do we actually check if the impedance of the amp and preamp would be matched? i saw that they are measured in "kohms" like 20kohm/30kohms etc?

is it simply making sure that the input impedance on the amp should be greater that the output impedance of the preamp?

Thanks...