[ratso]

i have a squeezebox 3 modded by wayne at bolder cable. it sounds great, but the mod dropped the output to only 1.1v so it needs a gain boost to get the needed db's to listen to it. i decided to go with dusty's headphone amp to be used as a preamp to get the needed gain in a simple clean manner. at the 15db gain setting on the headphone amp i am usually running close to full volume at 'wife's not home' listening levels. in other words i need a bit more gain. i contacted dusty asking if he could mod the amp and he said yes, but he wouldn't advise it. however (i guess being holidays and all) i think he was busy and didn't elaborate as to what the drawbacks were.  i was looking for about 5 db more. i was wondering if anyone knew:
1. what is the drawbacks behind modding the amp (would the sound suffer, lifespan decrease, etc.). i'm guessing it's a sound quality issue and would like some help deciding if the trade off would be worth it - a slight quality loss vs. a needed gain increase?
2. i don't know if i'm WAY off base here, because i know nothing about this - but would it be better to use a phono preamp instead? could you input a squeezebox into it? at 40db it would be twice as loud but i would rather have my volume set down 50% rather then cranked 50%. thanx!

[DSK]

Ratso, if you are using the analog output of the Bolder modded SB, then adding a Burson Buffer will add 6dB (this is more than it sounds). There are some reasonably current threads on this that explain the effect heard by those who have gone this route... try the Bolder circle. It is relatively inexpensive and will give you all the drive, slam, chutzpah and volume you need.

BTW, you do not want to add so much gain that you can only use the lower sector of the SB volume control. The higher you can keep it, while having enough headroom to crank up quieter recordings, the less degredation it will have on the signal/music.

[ratso]

thanx for the response D - it was actually waynes response that led me to the headphone amp. he stated that 6 db gain in the buffer was sufficient for some but around 9db would be good for most. these numbers seemed to match well with dusty's amp which puts out 6-15db. however it turns out in my system i need more like 20db.  i think that 9db is the most that a buffer can be maxed out to which wouldn't cut it. besides i like dusty's stuff a lot more. my sb3 volume is maxed. i think i could keep it close to max and just use the main gain control with any setup, because the mains are close to max now. sound quality isn't the issue - it sounds great!

[JLM]

And BTW, a phono pre-amp also makes the RIAA standard conversion from stylus "wiggle" velocities (that is what generates the signal) into the amplitude of the wiggle (which is the true representation of the original signal).  So you won't want to use a phono pre-amp for anything else.

Another idea, if you own CIA amps.  Dusty used to offer 26 and 32 dB gain versions of his amps for pre-amps with and without gain.  Perhaps you have a 26 dB version and he can switch it to 32 dB.

[richidoo]

A stock Burson buffer is not up to the sound quality of the modified SB, and doesn't give you enough gain anyway. You may be able to improve things by getting some short, low capacitance IC cables to reduce the load on the DAC, but your gain will not increase without an amp stage.

What you really need is an active preamp that makes 20dB+ gain. This is exactly what a preamp is for, and will give you silent, good sounding gain to compliment your great source. Contact Steve Sammet of SAS Audio. He can explain why a real preamp is the best way to solve your issue, or just read articles on his website to get the concept.

A Eastern Electric Minimax is a great sounding tube preamp with the gain you need. Used for about $600, or new with importer Bill O'Connell's excellent support. I have not found a solid state preamp at this price range that retains the subtle musical qualities of a source as good as Wayne's SB, not many at high prices either. For small signal gain, tubes are the way to go, IMO. One of the best tube preamp circuits out there is Aikido, which you build from a kit. Good quiet power supply is essential, so good tube preamps are not as cheap as SS.
Good luck!
Rich

[CIAudio]

at the 15db gain setting on the headphone amp i am usually running close to full volume at 'wife's not home' listening levels. in other words i need a bit more gain. i contacted dusty asking if he could mod the amp and he said yes, but he wouldn't advise it. however (i guess being holidays and all) i think he was busy and didn't elaborate as to what the drawbacks were.  i was looking for about 5 db more. i was wondering if anyone knew:

There is no problem running close to full volume. My point was there is no reason to add more gain unless you cannot reach your desired listening level.

1. what is the drawbacks behind modding the amp (would the sound suffer, lifespan decrease, etc.). i'm guessing it's a sound quality issue and would like some help deciding if the trade off would be worth it - a slight quality loss vs. a needed gain increase?

There is no drawback other than the added cost of modification.

2. i don't know if i'm WAY off base here, because i know nothing about this - but would it be better to use a phono preamp instead? could you input a squeezebox into it? at 40db it would be twice as loud but i would rather have my volume set down 50% rather then cranked 50%. thanx!

You cannot use a phono preamp because it has a built-in EQ curve for RIAA equalization.

[ratso]

You cannot use a phono preamp because it has a built-in EQ curve for RIAA equalization.


[/quote]

thanx for your very helpful insights. knowing this, i think i will send the amp to dusty to be modded.

[sts9fan]

What kind of speakers and amp are you using and what size room?  Why use a head amp to do a pre-amps job?

[CIAudio]

Why use a head amp to do a pre-amps job?

Actually, the VHP-2 works great as an active preamp...but also has the ability to drive lower impedance loads (like headphones).

[ratso]

well actually sts that's a pretty fair question. i originally wanted to use only dusty's 2 channel passive preamp because i only have 2 input sources - my squeezebox for music and my a/v reciever for video processing kept seperate from the music on the other channel.  i had an idea to build a 2 channel reference system as economically as possible. i decided to put the majority of my meager funds into as good as speakers as possible (my gallo 3.1's). the amps are reasonably priced (quad emotiva bpa's drive the speakers as monoblocks). when it became apparent that i needed some gain, i originally wanted to go with a buffer but as mentioned above i went with ci headphone amp for simplicity and price. adding a full blown preamp would fix my problem but also add a lot of cost and complexity to my system. i am VERY happy with how it sounds, just a little more gain would make it (to my ears) PERFECT.