3 Input Headphone Amp -- Pre-Production Units Available

arethustra · 05-29-2003, 05:10 PM

As you know I have been working with Tesseract to bring a 3 input cross-fed headphone amp to market (If you didn't know you do now...).

Well, the pre-production units are now available in limited supply...

I have 3 pre-production units (only difference between these and the production units will be the face plates - these have the labelling engraved whereas the production units will be silk screened other than that they are the same; no difference in the board, circuit or components) available to sell...These units will sell for $110 which is about $30 off from retail as they are sans the silk screen front labelling...The first 3 to PM me will get the units...Payment either via PayPal or money order...

These units will come with a starter set of cords - we do have them in varying length so we can work with you on that. The unit itself, for those of you not following the previous thread, has 3 mixed inputs - one stereo, and two mono - that allow you to do things such as listen to your iPod, GPS and Radar Detector (you can also monitor your cell phone but, not speak) all from one set of speakers or ear buds. It operates off of one 9v battery with an average life expectancy of between 24-31 hours...The unit is in an aluminum enclosure and measures approximately 1" H x 2.5" W x 4" D - see the picture below - unit without labelling...

-Todd

arethustra · 05-30-2003, 12:27 PM

FYI...We're down to 2 units available...

arethustra · 05-30-2003, 02:08 PM

Quote:

Said arethustra:
FYI...We're down to 2 units available...

We're down to one now...1st one to PM me gets it...

tesseract · 06-01-2003, 05:43 AM

Attached is a picture of the pre-production mixer/amplifier. The whole purpose of this unit was, originally, to satisfy a request of Arethustra's: how can I listen to my music and monitor my radar detector at the same time? Originally I was going to just make him a passive mixing cable and be done with it, but then he wondered how much harder it would be to make the music louder? And then there was another person on the forum, Shelborn, I believe, who wondered if a third input could be added for his talking GPS navigator. Then the complaints about the Boostaroo's sound quality came in and so the high-fidelity audio amplifier mixer for motorcycle and home use was born. I am an audio fanatic so I designed the circuit and selected high quality parts so that it would sound good enough to compete with some very high-brow dedicated headphone amplifiers out there (like the Corda Porta-Corda and Headroom's AirHead). The relevant stats for the unit are:

9dB overall gain (almost a doubling of loudness)

Pure Class A operation of the low-level driver stage for the best linearity

True mixer inputs that turn 1 stereo and up to 2 mono inputs into 1 stereo output

A switchable "crossfeed" circuit that helps eliminate the eerie feeling you can get listening to music through headphones because of the total separation of the right and left channels - this circuit does not affect the "tone" of the sound at all.

The best-sounding op-amps for the power drain were selected by true A/B testing of them in otherwise identical units. Many sounded excellent, but the TSH22IN had the lowest current draw to boot.

Estimated battery life with one alkaline 9V battery is 24-27 hours, based on a battery capacity of 565mA/hr. A Radio Shack NiMH 9V lasted a little over 6 hours before distortion set in.

The case is made from black-anodized extruded aluminum. No girly plastic for the production models! The front faceplate on the pre-production units has the function labels engraved in. (We will probably apply a silkscreen to the top of the box for the production models.)

Contact Arethustra through PM for more information on the business end of this stuff - I am just the guy that designs and builds these things. Oh, one last thing: we will be including a basic set of cables to get you up and running immediately - none of this $49.95 for the necessary cables crap like one company that comes to mind (you know who if you've been looking around!). Also note that this is not an intercom system! This device could take the headphone output of an existing intercom system and add some high quality tunes to it, though, with the benefit that the tunes will not be distorted by the typically mediocre quality of an intercom's headphone amplifier.

Thanks for looking!

arethustra · 06-01-2003, 09:20 AM

All the pre-prod units are spoken for...to those of you that PM'ed me yesterday sorry I didn't get back to you sooner! I went by the timestamp on all PM's recieved and HackyMoto was first in line after the first two members that PM'ed me...So, the last last unit is his...For the rest of you that are interested we will make another LARGER batch of units available within the next 2 weeks...If you wish to reserve a unit please PM me and we'll get you on the list. Hell, I have to get on the list I still don't have one of the finished units...

FYI - The main holdup is unit labelling...We're looking into silkscreening the control labels etc. on the top of the unit but, have not found a good source to handle this for us (If you have a silkscreening or engraving business that can handle this and want some business PLEASE PM me!). The engraving isn't really an option that we can use unless the price comes down signifigantly as the panel as displayed above cost almost $20 just for the engraving which is just way to much money...

Thanks to all of you for your interest!

-Todd

JohnTM · 06-01-2003, 02:45 PM

If there are, I want two, please!

Johntm

arethustra · 06-02-2003, 08:52 AM

Quote:

Said johntm:
If there are, I want two, please!

Johntm

Yes, we will begin offering kits in the very near future - I think Johntm is going to be our guinea pig

- Once we have them organized we'll be offering them with several options, pricing-wise - for instance, we'll offer just the circuit board and parts list, circuit board and parts (no enclosure), or the whole enchilada - circuit board, parts and enclosure...

If you're interested in the DIY method just drop me a PM and we'll get you a kit assembled...

-Todd

sinnyc · 06-02-2003, 05:07 PM

After emailing back and forth with Tesseract a bunch in the last few days and being the impatient little bastard I am I got my amp in the mail today.

First impression: "Wow! Some guy out there *made* this? I must be much dumber than I thought."

Second impression:
Overall build quality is quite good.
The case is metal and solid.
The face plate is clearly marked and no nonsense.
The battery cover closes firmly and securely.
The included cabling was fine. The input cables chosen are well thought out in that they are "connected" at one end (the end that you would plug into the amp) which will help prevent cable spaghetti.

Upon arriving home I immediately plugged in my old MP3 player at half volume. I then jacked it through the amp and got a significantly louder, fuller sound. I had my girlfriend try and she concurred. Since I don't have access to my radar detector at the moment, I next plugged in a 2nd music source and experienced the same thing - louder, fuller and, of course, both sources simultaneously. As far as the crossover circuitry goes, I had no way to tell but since reading about the impedance issue in the main thread I have no doubt that I will not be burning out my V-1 remote sound unit.

I have nothing against Autocom – in fact I was about to buy one before I stumbled onto the original thread – but there are a few things I like about this unit more.
First, my main need is to have my radar detector and my iPod run into the same headphones.
Second, since I have no use for inter or intra bike communications, Tesseract’s amp is all I need.
Third, this amp is cheaper then any of the Autocom units I priced on the web.
Fourth, I think it is way fucking cool to own a device that one guy built after his buddy mentioned that he needed something that didn’t seem to exist. I would always rather spend my money with someone like that.
Fifth, it just plain makes me happy to see ADVrider do what it does best: disseminate information between people with similar interests. And generally foul mouths. Or is that just me? :)

Bottom line: I just got it so I reserve final judgment until I return from the Road America superbike races this weekend. So far though, I am completely satisfied both with the unit itself as well as with my ongoing communications with Tesseract. He has been nothing but prompt and accommodating – thanks a lot, man. The only thing I want now is an adapter that I can plug into one of the cigarette lighters I have on my bike. And he is already thinking about that!

arethustra · 06-03-2003, 10:53 AM

Glad to hear you like the unit thus far! Please let us know what you think after you get a chance to try it for a while...Both tessereact and I really want the feedback as it drives the product development - as in the case with the bike power cable which we are getting resolved ASAP.

We are still in the process of ironing out all the details so documentation and warranty information is, understandably, a bit thin...We'll get that corrected in the very near future (my job) and we'll also have a website up in near term to handle the information and ordering side of things as well (again my job)...Suffice it to say, if you don't think the unit lives up to our claims please return it and we'll refund you the purchase price less shipping and handling (the unit must be returned in good shape with all cables etc.) - Sort of a 30 day test drive, if you will...We'll also cover any manufacturers defects, subject to our inspection of the unit, for up to a year - we'll either repair the unit or replace it, at our discretion, to correct the problem.

Enough of the that...Enjoy the units more will be available soon!

Regards,

-Todd

rcompton · 06-06-2003, 06:36 PM

Please keep us updated on availability! I am ready to take the plunge. ...

One ? though:

Will you be resolving the external power issue before any more units are produced? Or will the next batch be retro-fittable for external power? Seems petty, but batteries are a drag and it would make everything clean if I could integrate everything into my tankbag.

Oh, one other ?:

I have looked around a bit for a somewhat weather-proof mini plug jack (1/8") I would like to integrate into my tankbag ala a Powerlet Powermat, so I just have one external plug than I can plug into.... (If that could be an option you could look at, all the better).

I would love to have one early July for a couple trips I have coming up.... :):

tesseract · 06-06-2003, 07:40 PM

I built a retrofit power adapter today that has absolutely no noise suppression circuitry on it and so far I haven't picked up any noise on the two cages I've tried it on. I'll be sending out a couple of power adapters to my pre-selected guinea pigs on Monday so with their feedback I should be able to get something rolling later next week. The fact that the amp as it is picks up no noise was a surprise as I didn't put too much effort into that aspect (seeing how Arethustra wanted it to run off of batteries...)

The tank bag feedthrough idea had already been mentioned to me and it'll be no problem to do, I just have to give it some though as to how to make it easily producible. The last thing I want to do is spend my days stripping cable and soldering it onto bulkhead jacks!

tesseract · 06-07-2003, 02:57 PM

We've given it a name that is much shorter than "3 input blah, blah, blah..." - xma3.

More importantly, 4 units are ready to go just as soon as the labels come in. The printers promised to have them ready by Tuesday, June 10th. Production won't go into full swing until the end of next week, though, so if you are in a hurry to get one, better send Arethustra an e-mail now as they will be sent out on a first-come, first served basis.

The power adapter I had been working on today will not work with other vehicle powered devices (in retrospect it was obvious, but hey, nobody's perfect...) so a different design was cooked up which isolates the vehicle power from the actual xma3 circuitry, just like a battery does. This will prove to be an almost universally effective solution because it neatly sidesteps the possibility of noise coming in through the power connection via ground loops, and ground loops are the number one source of noise.

The way I will implement the external power connection is by mounting a dc power jack on a replacement battery compartment door which will connect to the dc-to-dc converter modules that provides the necessary isolation. The converter will connect to the xma3 through its battery snap so no modification - just a swapping of battery compartment doors - will be necessary to convert the unit to externally powered operation. The input voltage will span a fairly wide range so pretty much any old wall wart or cigarette plug adapter should power the thing as long as it has a 2.1mm barrel plug on it with center positive (I may be able to make it polarity insensitive, but that'll depend on how much junk I can cram into the available space).

The power adapter module should cost around $15 to $20 and will come with your choice of power cord (cigarette lighter plug, SAE-2 connector, pigtails + inline taps (!?!))

The cost of the xma3, once again, is $125 for AdvRider forum members.

arethustra · 06-24-2003, 05:42 PM

The XMA3 (formerly known as the '3 Input Headphone Amplifier') is now available...

The XMA3 is now available in two configurations:

1.) 9v Battery Powered
2.) Bike Powered via a Cigarette Lighter Adaptor

Due to savings realized on the labelling (For those of you following the thread we didn't end up utilizing silk screening due to the costs involved and the # of units that we had to have done in a lot; Also there were some durability issues during our testing of the longevity of the silk screened labelling) the unit prices are as follows:

$110 + Shipping for the Battery Powered Units
$125 + Shipping for the Bike Powered Units

Please PM me to place an order - Please indicate your email address, shipping address and unit type preference - battery or bike powered. Payment instructions will be delivered in a follow-up PM.

arethustra · 06-24-2003, 05:45 PM

The two power choices...

g_e_young · 07-13-2003, 09:58 PM

Do you recommend any particular in-helmet speakers to go with this device?

Thx,

grant-

05-29-2003, 05:10 PM	#1
arethustra ^OP California dreamin' Joined: Jan 2003 Location: San Francisco, CA. Oddometer: 565	3 Input Headphone Amp -- Pre-Production Units Available As you know I have been working with Tesseract to bring a 3 input cross-fed headphone amp to market (If you didn't know you do now...). Well, the pre-production units are now available in limited supply... I have 3 pre-production units (only difference between these and the production units will be the face plates - these have the labelling engraved whereas the production units will be silk screened other than that they are the same; no difference in the board, circuit or components) available to sell...These units will sell for $110 which is about $30 off from retail as they are sans the silk screen front labelling...The first 3 to PM me will get the units...Payment either via PayPal or money order... These units will come with a starter set of cords - we do have them in varying length so we can work with you on that. The unit itself, for those of you not following the previous thread, has 3 mixed inputs - one stereo, and two mono - that allow you to do things such as listen to your iPod, GPS and Radar Detector (you can also monitor your cell phone but, not speak) all from one set of speakers or ear buds. It operates off of one 9v battery with an average life expectancy of between 24-31 hours...The unit is in an aluminum enclosure and measures approximately 1" H x 2.5" W x 4" D - see the picture below - unit without labelling... -Todd Attached Images

06-01-2003, 05:43 AM	#4
tesseract Adventurer Joined: May 2003 Location: Tampa, FL Oddometer: 44	Attached is a picture of the pre-production mixer/amplifier. The whole purpose of this unit was, originally, to satisfy a request of Arethustra's: how can I listen to my music and monitor my radar detector at the same time? Originally I was going to just make him a passive mixing cable and be done with it, but then he wondered how much harder it would be to make the music louder? And then there was another person on the forum, Shelborn, I believe, who wondered if a third input could be added for his talking GPS navigator. Then the complaints about the Boostaroo's sound quality came in and so the high-fidelity audio amplifier mixer for motorcycle and home use was born. I am an audio fanatic so I designed the circuit and selected high quality parts so that it would sound good enough to compete with some very high-brow dedicated headphone amplifiers out there (like the Corda Porta-Corda and Headroom's AirHead). The relevant stats for the unit are: 9dB overall gain (almost a doubling of loudness) Pure Class A operation of the low-level driver stage for the best linearity True mixer inputs that turn 1 stereo and up to 2 mono inputs into 1 stereo output A switchable "crossfeed" circuit that helps eliminate the eerie feeling you can get listening to music through headphones because of the total separation of the right and left channels - this circuit does not affect the "tone" of the sound at all. The best-sounding op-amps for the power drain were selected by true A/B testing of them in otherwise identical units. Many sounded excellent, but the TSH22IN had the lowest current draw to boot. Estimated battery life with one alkaline 9V battery is 24-27 hours, based on a battery capacity of 565mA/hr. A Radio Shack NiMH 9V lasted a little over 6 hours before distortion set in. The case is made from black-anodized extruded aluminum. No girly plastic for the production models! The front faceplate on the pre-production units has the function labels engraved in. (We will probably apply a silkscreen to the top of the box for the production models.) Contact Arethustra through PM for more information on the business end of this stuff - I am just the guy that designs and builds these things. Oh, one last thing: we will be including a basic set of cables to get you up and running immediately - none of this $49.95 for the necessary cables crap like one company that comes to mind (you know who if you've been looking around!). Also note that this is not an intercom system! This device could take the headphone output of an existing intercom system and add some high quality tunes to it, though, with the benefit that the tunes will not be distorted by the typically mediocre quality of an intercom's headphone amplifier. Thanks for looking! Attached Images

06-01-2003, 09:20 AM	#5
arethustra ^OP California dreamin' Joined: Jan 2003 Location: San Francisco, CA. Oddometer: 565	UPDATE All the pre-prod units are spoken for...to those of you that PM'ed me yesterday sorry I didn't get back to you sooner! I went by the timestamp on all PM's recieved and HackyMoto was first in line after the first two members that PM'ed me...So, the last last unit is his...For the rest of you that are interested we will make another LARGER batch of units available within the next 2 weeks...If you wish to reserve a unit please PM me and we'll get you on the list. Hell, I have to get on the list I still don't have one of the finished units... FYI - The main holdup is unit labelling...We're looking into silkscreening the control labels etc. on the top of the unit but, have not found a good source to handle this for us (If you have a silkscreening or engraving business that can handle this and want some business PLEASE PM me!). The engraving isn't really an option that we can use unless the price comes down signifigantly as the panel as displayed above cost almost $20 just for the engraving which is just way to much money... Thanks to all of you for your interest! -Todd arethustra screwed with this post 06-03-2003 at 11:12 AM

06-01-2003, 02:45 PM	#6
JohnTM I suck toes Joined: Oct 2001 Location: Cornersville, TN Oddometer: 29,206	Any kits gonna be available? If there are, I want two, please! Johntm

06-02-2003, 05:07 PM	#8
sinnyc Ride harder, not smarter Joined: Apr 2002 Location: Minneapolis, MN Oddometer: 373	Got my prototype unit tody After emailing back and forth with Tesseract a bunch in the last few days and being the impatient little bastard I am I got my amp in the mail today. First impression: "Wow! Some guy out there made this? I must be much dumber than I thought." Second impression: Overall build quality is quite good. The case is metal and solid. The face plate is clearly marked and no nonsense. The battery cover closes firmly and securely. The included cabling was fine. The input cables chosen are well thought out in that they are "connected" at one end (the end that you would plug into the amp) which will help prevent cable spaghetti. Upon arriving home I immediately plugged in my old MP3 player at half volume. I then jacked it through the amp and got a significantly louder, fuller sound. I had my girlfriend try and she concurred. Since I don't have access to my radar detector at the moment, I next plugged in a 2nd music source and experienced the same thing - louder, fuller and, of course, both sources simultaneously. As far as the crossover circuitry goes, I had no way to tell but since reading about the impedance issue in the main thread I have no doubt that I will not be burning out my V-1 remote sound unit. I have nothing against Autocom – in fact I was about to buy one before I stumbled onto the original thread – but there are a few things I like about this unit more. First, my main need is to have my radar detector and my iPod run into the same headphones. Second, since I have no use for inter or intra bike communications, Tesseract’s amp is all I need. Third, this amp is cheaper then any of the Autocom units I priced on the web. Fourth, I think it is way fucking cool to own a device that one guy built after his buddy mentioned that he needed something that didn’t seem to exist. I would always rather spend my money with someone like that. Fifth, it just plain makes me happy to see ADVrider do what it does best: disseminate information between people with similar interests. And generally foul mouths. Or is that just me? :) Bottom line: I just got it so I reserve final judgment until I return from the Road America superbike races this weekend. So far though, I am completely satisfied both with the unit itself as well as with my ongoing communications with Tesseract. He has been nothing but prompt and accommodating – thanks a lot, man. The only thing I want now is an adapter that I can plug into one of the cigarette lighters I have on my bike. And he is already thinking about that! __________________ sinnyc IBA # 9436 '06 BMW R1200GSA \| '02 Triumph Daytona CE \| '02 KTM Duke II \| '75 Norton Commando Mk III "The collar bone is the fuse panel of the body y'know :)" - Geek, making a lucid observation

05-30-2003, 12:27 PM	#2
arethustra ^OP California dreamin' Joined: Jan 2003 Location: San Francisco, CA. Oddometer: 565	FYI...We're down to 2 units available...

06-03-2003, 10:53 AM	#9
arethustra ^OP California dreamin' Joined: Jan 2003 Location: San Francisco, CA. Oddometer: 565	Glad to hear you like the unit thus far! Please let us know what you think after you get a chance to try it for a while...Both tessereact and I really want the feedback as it drives the product development - as in the case with the bike power cable which we are getting resolved ASAP. We are still in the process of ironing out all the details so documentation and warranty information is, understandably, a bit thin...We'll get that corrected in the very near future (my job) and we'll also have a website up in near term to handle the information and ordering side of things as well (again my job)...Suffice it to say, if you don't think the unit lives up to our claims please return it and we'll refund you the purchase price less shipping and handling (the unit must be returned in good shape with all cables etc.) - Sort of a 30 day test drive, if you will...We'll also cover any manufacturers defects, subject to our inspection of the unit, for up to a year - we'll either repair the unit or replace it, at our discretion, to correct the problem. Enough of the that...Enjoy the units more will be available soon! Regards, -Todd arethustra screwed with this post 06-03-2003 at 11:17 AM

06-06-2003, 06:36 PM	#10
rcompton I am not Iron Man Joined: Mar 2003 Location: Atlanta! Oddometer: 2,519	Please keep us updated on availability! I am ready to take the plunge. ... One ? though: Will you be resolving the external power issue before any more units are produced? Or will the next batch be retro-fittable for external power? Seems petty, but batteries are a drag and it would make everything clean if I could integrate everything into my tankbag. Oh, one other ?: I have looked around a bit for a somewhat weather-proof mini plug jack (1/8") I would like to integrate into my tankbag ala a Powerlet Powermat, so I just have one external plug than I can plug into.... (If that could be an option you could look at, all the better). I would love to have one early July for a couple trips I have coming up.... :):

06-06-2003, 07:40 PM	#11
tesseract Adventurer Joined: May 2003 Location: Tampa, FL Oddometer: 44	I built a retrofit power adapter today that has absolutely no noise suppression circuitry on it and so far I haven't picked up any noise on the two cages I've tried it on. I'll be sending out a couple of power adapters to my pre-selected guinea pigs on Monday so with their feedback I should be able to get something rolling later next week. The fact that the amp as it is picks up no noise was a surprise as I didn't put too much effort into that aspect (seeing how Arethustra wanted it to run off of batteries...) The tank bag feedthrough idea had already been mentioned to me and it'll be no problem to do, I just have to give it some though as to how to make it easily producible. The last thing I want to do is spend my days stripping cable and soldering it onto bulkhead jacks!

06-07-2003, 02:57 PM	#12
tesseract Adventurer Joined: May 2003 Location: Tampa, FL Oddometer: 44	Status update on the mixer/amp We've given it a name that is much shorter than "3 input blah, blah, blah..." - xma3. More importantly, 4 units are ready to go just as soon as the labels come in. The printers promised to have them ready by Tuesday, June 10th. Production won't go into full swing until the end of next week, though, so if you are in a hurry to get one, better send Arethustra an e-mail now as they will be sent out on a first-come, first served basis. The power adapter I had been working on today will not work with other vehicle powered devices (in retrospect it was obvious, but hey, nobody's perfect...) so a different design was cooked up which isolates the vehicle power from the actual xma3 circuitry, just like a battery does. This will prove to be an almost universally effective solution because it neatly sidesteps the possibility of noise coming in through the power connection via ground loops, and ground loops are the number one source of noise. The way I will implement the external power connection is by mounting a dc power jack on a replacement battery compartment door which will connect to the dc-to-dc converter modules that provides the necessary isolation. The converter will connect to the xma3 through its battery snap so no modification - just a swapping of battery compartment doors - will be necessary to convert the unit to externally powered operation. The input voltage will span a fairly wide range so pretty much any old wall wart or cigarette plug adapter should power the thing as long as it has a 2.1mm barrel plug on it with center positive (I may be able to make it polarity insensitive, but that'll depend on how much junk I can cram into the available space). The power adapter module should cost around $15 to $20 and will come with your choice of power cord (cigarette lighter plug, SAE-2 connector, pigtails + inline taps (!?!)) The cost of the xma3, once again, is $125 for AdvRider forum members.

06-24-2003, 05:42 PM	#13
arethustra ^OP California dreamin' Joined: Jan 2003 Location: San Francisco, CA. Oddometer: 565	XMA3 Production Units NOW AVAILABLE The XMA3 (formerly known as the '3 Input Headphone Amplifier') is now available... The XMA3 is now available in two configurations: 1.) 9v Battery Powered 2.) Bike Powered via a Cigarette Lighter Adaptor Due to savings realized on the labelling (For those of you following the thread we didn't end up utilizing silk screening due to the costs involved and the # of units that we had to have done in a lot; Also there were some durability issues during our testing of the longevity of the silk screened labelling) the unit prices are as follows: $110 + Shipping for the Battery Powered Units $125 + Shipping for the Bike Powered Units Please PM me to place an order - Please indicate your email address, shipping address and unit type preference - battery or bike powered. Payment instructions will be delivered in a follow-up PM. Attached Images

06-24-2003, 05:45 PM	#14
arethustra ^OP California dreamin' Joined: Jan 2003 Location: San Francisco, CA. Oddometer: 565	The two power choices... Attached Images

07-13-2003, 09:58 PM	#15
g_e_young Studly Adventurer Joined: Sep 2002 Location: N Calif, USA Oddometer: 848	In helmet speakers Do you recommend any particular in-helmet speakers to go with this device? Thx, grant-

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