Jump to content
JimP

How to attenuate source so amp has more volume play??

Recommended Posts

OK I've gotten off the binge & purge wagon, and have settled in with 840c/Almarro/K1000 as my main rig (and Earmax AE for other phones like HD650). Now my main system is pretty much perfect (to me) except for one annoying thing:

840c is fixed out RCA to the Almarro integrated amp. Even with low 5wpc output of the amp and the K1000, I can only use the volume knob up to about 9 o'clock before it's too loud (maybe a bit more for classical/opera). That is, very limited range of volume knob. I wish the 840c had some kind of variable out option, then I could optimize so the amp volume can turn to, say, 10-12 o'clock.

Is there some device, like a passive line attenuator, even a passive line pre-amp, that I can put between source and amp, so that I can achieve relatively higher volume knob play? Obviously without sound/signal degradation.

Not sure if the above question makes sense, but I would really appreciate any input. Or should I just live with it?

Share this post


Link to post
Share on other sites

Without signal degradation is going to be the kicker. Honestly, the only good cure is to find a source with either a good built in preamp or live with the possibility that an inline attenuator is going to potentially degrade the signal slightly.

Share this post


Link to post
Share on other sites

Just use 2 resistors as a voltage divider (attenuator). A lot of amps have similar things in the signal path in addition to the volume control, before and/or after the volume control. You're not going to get more than 0.000001% distortion, just pick appropriate value resistors based on the source's output impedance, not too low and not too high

Share this post


Link to post
Share on other sites

Justin FTW!

These http://mysite.verizon.net/vze4c5pt/id2.html look nice, but you could do what you need to do with not even 4 resistors, but 2, one in series with each channel, for $0.40 apiece for nice resistors (PRP, Holco, etc.). Yes, you would want to probably solder these into the Almarro, right before the volume pot if you could. The pot will provide the resistance to ground required.

Share this post


Link to post
Share on other sites

Justin FTW!

These http://mysite.verizon.net/vze4c5pt/id2.html look nice, but you could do what you need to do with not even 4 resistors, but 2, one in series with each channel, for $0.40 apiece for nice resistors (PRP, Holco, etc.). Yes, you would want to probably solder these into the Almarro, right before the volume pot if you could. The pot will provide the resistance to ground required.

still impacts the signal path. My suggestion of ear plugs was the only one that keeps as pure as possible signal path, so there!

Share this post


Link to post
Share on other sites
still impacts the signal path. My suggestion of ear plugs was the only one that keeps as pure as possible signal path, so there!
Yeah, but ear plugs still color the sound -- quite a bit more than any interconnect or resistor will.

Share this post


Link to post
Share on other sites

Yeah, but ear plugs still color the sound -- quite a bit more than any interconnect or resistor will.

I think Nate got my point... :)

Share this post


Link to post
Share on other sites

the name goldenjacks seems slightly skeevy to me....

They are the same thing as the Rothwell attenuators, only without the extortionate pricetag. Two good resistors in a nice RCA plug/socket.

Share this post


Link to post
Share on other sites

We have bush! thanks beefy, I think I'll go for these. I ping'ed the guy selling the 'shotgun' ones and he says he's currently developing newer version, but I don't really need variable attenuation and don't want to wait. Skeevy is ok, as long the goldennuggets work. Question is, should I go for -10, -14, or -20? Again with K1000's, I'm only going around 8 o'clock before it's too loud.

(As an aside, I just tried my new (to me) DT880-600ohm straight out of Almarro HP jack -- sounds great! but even with 600ohm, I'm around 8 o'clock on the vol. dial. so now doubly motivated to get this attenuation thing worked out)

maybe I'll go -20 and make sure he allows me to return to go down if necessary.

Share this post


Link to post
Share on other sites

Question is, should I go for -10, -14, or -20? Again with K1000's, I'm only going around 8 o'clock before it's too loud.

If you can find the lineout voltage and input impedance of your amp, then drop him an email and ask. He should be able to calculate the best set for your needs.

In any case, I personally suspect that the -20 would be too much. The -6dB does literally give 50% volume at the same pot setting for me - I tested by putting a jack on one channel only, listening, then switching it over.

Share this post


Link to post
Share on other sites

the goldenjacks guy was extremely helpful, he went out of his way to research the 840c and Almarro on his own. I put an order in for a -14dB set.

Share this post


Link to post
Share on other sites

I should probably get some of these too, I'm in the same 8 o'clock situation, and that's with the 'low' output setting on my amp with the Staxes!

Share this post


Link to post
Share on other sites

Cool solution! I hope they work well. Let us know.

Share this post


Link to post
Share on other sites

OK I just got these goldenjacks, -14 dB version, so far they seem to do the trick. I'm not a cable/plug freak but these are the nicest plugs I've ever seen:

Picture003.jpg

Before I was severely limited with my volume knob from 7 o'clock to 8 o'clock (very annoying). Now I can go to about 10 o'clock on the K1000, and 9 o'clock on the DT880-600ohm - a bit more with classical music (maybe I should have gone with the -20 dB version?). Tried it on my Bryston B60R as well, and gives me a lot more volume control play with the HD650 (may order another set for the B60R). Does it degrade/alter sound? I don't know/I can't tell/I'm not going to obsess over it. Will report back after some longterm listen. BTW, the goldenjack dude is very helpful. [YMMV, the 'culprit in my system is the 840C - a wonderful DAC and CD player - CD player mode severely restricts my volume levels compared to DAC only]

Share this post


Link to post
Share on other sites

Also I will add that now I can use the DT880-600ohm effectively out of the Almarro, this is quite an amazing combo - huge soundstage, fulsome sound, no sibilance, tons of detail (better than out of my Earmax AE). Yes, the K1000 may better it, but the gap is pretty narrow. These goldenjacks are worth it, if only in elevating my DT880-600ohm. Right now 70% of my listening is DT880-600ohm, 20% K1000, 10% HD650. [Do not mistake these DT880-600ohm with other DT880 versions]

Share this post


Link to post
Share on other sites

Just read this post now, WoW they do look good.

Could probably whip something up DIY but this looks a lot neater

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×