Sprout preamp


#1

looking to use the Sprout as a preamp to drive an alternate power amp. My question is with this config, can the cause damage to the power amp section of Sprout due to no load present?


#2

Nope, none whatsoever. Many people use Sprout just like this and its internal power amplifier is happy twiddling its electronic thumbs.


#3
Paul McGowan said . . . its internal power amplifier is happy twiddling its electronic thumbs.
:)

#4

I was fortunate enough to be one of the original “crowdfunding” supporters of Sprout. I have been using a pair of Sequerra Pyramid speakers with T-1 ribbon tweeters. These are huge power hungry speakers that require big amps, or so I thought. When my two PS Audio 200C amps (one per side) were destroyed in a basement flooding catastrophe, along with my PS Audio preamp, I was not sure what to do. I got the Sprout and tried powering these monster speakers with it. Unbelievably, that little box did an amazingly good job. I then acquired a vintage Adcom power amp (200 watts per channel), used the Sprout as a preamp, and couldn’t be happier. Not exactly true. A pair of BHK monos would make me happier.


#5

Are you using a 3.5 banana-plug-to-RCA cable to go directly into an amplifier? I have a Threshold SA/3 power amp and a SW-200 Subwoofer amplifier that I’d like to connect to a Sprout.


#6

I am running 3.5 to RCA from Sprout to my amp. From the amp directly to my speakers. Additionally, I ran speaker wire from the Sprout output to my high level inputs on my sub woofer. This is working amazingly. I didn’t want any connections between the amp and speakers, so chose this configuration, and as mentioned, is working wonderfully…


#7

If I use the Sprout as a preamp only and connect the sprout to a power amp thought the 3.5mm output, will the amount of power used to drive the speakers be entirely dependent on the amount of power the power amp has? In other words if the power amp has 35W, then the speakers will be driven by 35W and the Sprout has no effect on the amount of power. Do I have that right?


#8

Yes, that is correct. The new add on power amp can be as small or big as you wish and whatever its power level will be what’s used to drive the speaker.


#9

Since the analog out on the Sprout is controlled by the volume control on the Sprout itself, where would you recommend I set the volume, assuming that the power amp has its own volume control?


#10

You want the volume control to be at about the 2 PM level on the dial for pretty loud.

But why use the Sprout at all as a preamp, in that case? If you have a power amp with a volume control (usually referred to as an integrated) why add another preamp in front of it? It would make sense if you’re using Sprout as a DAC/BlueTooth etc., but as a straight preamp into another preamp/amp combo, I am confused.


#11

Well, most of the power amps I’m looking at that are labeled as power amps have volume controls. I’m confused about why that is the case myself, but I am hardly an expert on this.

The main reason I’m looking into power amps at all is that while I love the Sprout, I’m not happy with the bass performance of the Sprout with my MMGs. The bass is quite well defined but lower in volume than the rest of the music.

I’m reading some information that argues that the MMGs need a bit more power than the Sprout can provide. I’ve also wondered if the bass rolloff the Sprout has (not the boost) doesn’t allow the MMGs to play bass as well as they might be able to. My idea is to bypass Sprout’s power amp and add a bit more power.


#12

Ok. Understood. But, you do know Maggies haven’t any bass (to speak of) in the first place?

I have owned many a pair (they’ve graced my listening rooms for years) and have always coupled them with a subwoofer. They really need one. You’ll certainly get better bass performance with a bigger amp, but depending on what your expectations for bass are, you might consider spending your money on a decent sub instead. I guarantee you’ll be happier with one than not.


#13

Yes, I am aware that they will never have the bass response of box speakers. But I do still think they can do better.

I have tried a few subwoofers, and the main issue I have is that, while I am able to pair them well with the Maggies on some music, on other music they will sound very out of sync. I don’t want to have to adjust the sub depending on what kind of music I play. It could be that I need to be more patient, but from my perspective pairing a sub to one’s speakers is not very straightforward.


#14

There’s a trick to making that work. First, make sure the sub you get is fast enough to match the Maggies. Like a small REL.

Second, run the low pass filter low. Lower than you might think. I wouldn’t go any higher than 50Hz.

Second, tune the level to an instrument like an acoustic stand-up bass. You want just enough level that the bass sounds real, never drawing attention to the sub.

If you ever “hear” the sub, then it’s too high in frequency or too loud in level.

There’s no question it can be done so you never know it’s there and all the sound is quick and planar-like from the Maggies.


#15

I purchased a Martin Logan subwoofer. I chose it partly because it was on sale but also for its compact size and most importantly because the crossover lowest setting was 45Hz. There were other good options that were priced reasonably and had good reviews, but I wanted to follow your recommendation to set the crossover at no higher than 50Hz.

I then used a track from Blossom Dearie’s album of Comden and Green songs, which has an extended string bass intro, which is very up front in the mix. That made it easy to set the gain at around 1 o’clock. It tried a bunch of other tracks, but I always ended up at 1 o’clock after minor adjustments.

Thanks so much for your help!