Preamp has too much gain


Hi.
This is my first post here. I have a Consonance Reference 1.1 preamp that has too much gain. Is there anyway I can reduce the gain without any loss to the sound and does any member know how I can go about purchasing a schematic. I try to fax them, but their tel. number is not in service.
electra
A quick and easy method is to install an in-line attenuator between your pre-amp and amp. There are typically classified ads here on AudiogoN for a Rothwell 10bd in-line attenuator. I've never used them, but the subject comes up often and I've read that they don't seem to have a negative impact on overall sonics.

Personally, I would prefer this method to modifying the circuit. I wouldn't want to do anything to the unit that may damage it or lower its resale value.

Enjoy,

TIC
I have a Consonance Reference 1.1 preamp that has too much gain.

I'm assuming by this you mean it is too loud with the volume barely turned up, but your assessment of the problem is not correct since you never use the gain that the preamp has. The stated gain of the pre is with the volume all the way up, but you don't have it all the way up (the preamp is attenuating the signal all the time instead of amplifying it) so the problem is it doesn't attenuate enough and/or the steps are too big (and here is the important part) for your combination of components.

It is normal to blame the pre because that is where the volume control is, but that isn't the correct analysis. You need a source that puts out less voltage, or a pre with more attenuation, or an amp that has less gain, or speakers that are less efficient, or some combination of these.

In line attenuators as suggested is one approach, or find components that go together better.
Very easy to fix, just need couple of high-quality resistor to construct a voltage divider.

Assuming your preamp has an input impedance of 100kOhm, then, to reduce the gain to 1/3, you can insert a 200kOhm resistor in series to the input RCA.

The gain will be reduced by 100k / (200k + 100k) = 0.33x, i.e. 1/3 in this example.

You can also use a high quality variable resistor, such as a Bournes pot then you can adjust the gain with a screw driver.
You need a source that puts out less voltage, or a pre with more attenuation, or an amp that has less gain, or speakers that are less efficient, or some combination of these.
Herman (System | Reviews | Threads | Answers)
Bingo.
What Extremephono suggests is precisely what Lamm Industries did to attenuate the gain in my LL2 Deluxe. $80. For a non-Diy'er, it was money well spent...and less expensive than variable inline attenuators. It's also easily reversible.

However, I needed to know the input gain of my amp for Lamm to know how to adjust the preamp.
Wow, answers to a question I didn't even know I had. I have the same pre as Electra and always wondered why I could only turn it up to about the nine oclock position, (with zero being about 7 oclock), without it being too loud for your average listening session. My source is a Sim Audio Moon Eclipes, my amp is a Redgum, forget the model but it's about 150wps, speakers are Osborn Grand Monument Refs. Am I going to get a better/ different sound by doing some of the changes you have recomended, or does it really matter where the dial is set?
One of the few things that designers will agree upon is that the closer you operate to maximum volume then the better the sound. Volume controls always take away. The ideal system would have an overall gain (source + preamp + power amp + speaker efficiency) that plays a particular recording at the ideal volume level with the volume control all the way up.

I’m not talking about loud volume, but the maximum that a system will allow. The problem is that the level from recordings varies widely and we want to listen to different types of music at different volumes, so the maximum volume is often too loud.

If you consistently have the volume control way closer to the minimum than the maximum then the volume control is choking some of the life out of your system.
The electronics should be run at the highest possible gain, at a given supply voltage, where feasible. For example, if the line stage is designed for 20dB of gain, and you run it at 5dB, the THD will go up tremendously, and the circuit may even become unstable. The higher gain also gives you the best S/N ratio.

It's the right way to pad down the signal level, then to lower the gain. The noise in the system is typically 'White', so the less gain, the less useful dynamic range.
I also had a gain issue. I installed rothwell 10db attenuators between my cd player and pre-amp and that solved the problem.

Chuck
The electronics should be run at the highest possible gain, at a given supply voltage, where feasible.

I don't understand. How would you lower the gain of a preamp without major reconstruction? THD comes from operating an active device in a non-linear manner. The operating point (bias) of the active device determines where you are on the curve and this isn't really related to gain so THD really isn't related to gain except in the sense that it will increase if you allow the signal to become so large it swings into the non-linear portions of the device's curves. It's a bit more complex than that since bias and operating points can affect gain but that's the basics. Maybe I'm missing something here.