Member
Joined 2003
I've half-assed wired everything up on this amp and hooked it to my speakers. Initial impressions are very good. The only thing I can compare it to is my previous amp which was a NAD T770 reciever. I will admit that this does sound a fair bit better. Definately more detailed sound and at first impression I think this is about on par with the NAD in terms of "brightness". There is a small bit of hum at the speakers if I turn the volume all the way up (which I'm sure is very loud as normal listening volume is 1/4 turn of my log pot), but I haven't connected my chassis to the mains ground so hopefull that should help with things as well as cleaning up my wiring a little.
FYI, I am listening through my computer which has an M-Audio audiophile 2496 soundcard. My speakers consist of a pair of bookshelfs (6.5" peerless CSX 850122 and Peerless 811815 tweeter) and an Ascendant Audio Atlas 12" subwoofer.
I still have to hook up my rotary switch so I can connect multiple inputs, as well as polish my chassis. It is a used aluminum chassis that looks pretty junky right now...until I polish it that is.
FYI, I am listening through my computer which has an M-Audio audiophile 2496 soundcard. My speakers consist of a pair of bookshelfs (6.5" peerless CSX 850122 and Peerless 811815 tweeter) and an Ascendant Audio Atlas 12" subwoofer.
I still have to hook up my rotary switch so I can connect multiple inputs, as well as polish my chassis. It is a used aluminum chassis that looks pretty junky right now...until I polish it that is.
Try turning it all the way up with no sources connected to see if there is still any hum.
Congrats!
Congrats!
Member
Joined 2003
I disconnected the input from the Freebird and the hum became quite a bit worse, actually. Noticeably audible with the pot at 1/2 turn.
In fact, now that I listen closer, with the input connected, the hum is barely audible at 1/2 turn of the pot, then nearly dissapears at a full turn, but at a full turn there is a noticeable amount of noise (not that I'll ever be listening to music at that volume). I'd say the noise level is similar to the amount present in my dads old '70s Realistic reciever.
Perhaps some better internal wiring would help? I am using hand twisted pairs of 24 guage wire. Should I maybe replace the wires with some microphone wire?
In fact, now that I listen closer, with the input connected, the hum is barely audible at 1/2 turn of the pot, then nearly dissapears at a full turn, but at a full turn there is a noticeable amount of noise (not that I'll ever be listening to music at that volume). I'd say the noise level is similar to the amount present in my dads old '70s Realistic reciever.
Perhaps some better internal wiring would help? I am using hand twisted pairs of 24 guage wire. Should I maybe replace the wires with some microphone wire?
I didn;t realize you had the freebird there (saw it on the other thread 😉 ). Try shorting the inputs to the freebird (RCA center pin to RCA shell ground) and see what kind of noise you get.
I have mine wired with some 24gauge wire from CAT5 cable (single pair) cause I have a ton of it.
I have mine wired with some 24gauge wire from CAT5 cable (single pair) cause I have a ton of it.
Me too at first had a bit of hum. Connecting the dissipator to ground via 10k resistor the hum gone away.
Welcome to the fun!
I've done that before...with heatsinks. I located chip screw holes where they were half in the fins. My advice,... I think I'll follow it... is to position the chips so the holes required go into the space between fins. It will make tapping the holes so much easier.
Regarding hum, Do you have any flourescent lights on the same circuit? That has tripped up more than a few.
I've done that before...with heatsinks. I located chip screw holes where they were half in the fins. My advice,... I think I'll follow it... is to position the chips so the holes required go into the space between fins. It will make tapping the holes so much easier.
Regarding hum, Do you have any flourescent lights on the same circuit? That has tripped up more than a few.
Member
Joined 2003
Ok so with shorted inputs there is absolutely no noise, but the hum is still barely audible (same loudness as with the inputs connected to the source). It's quite acceptable for me at this level, but of course it would be best to have no hum at all. There is flourescent lights in my ceiling and turning them off made no change. I am however finding it a little odd that the hum is only present with the volume pot at about 1/2 way. Tomorrow I'll ground the chassis, and move wires around while listening to see what is causing the hum. Today I am done though. Back to listening 😀
bg40403, the holes are lined up with the fins, but all the work on the heatsink was done at my friends metal shop, so with a big mother of a drill press there was no problem at all 😉
bg40403, the holes are lined up with the fins, but all the work on the heatsink was done at my friends metal shop, so with a big mother of a drill press there was no problem at all 😉
Hi Decible,
Congrats!
Not much time to post, busy night, but here is my take on your humm.
It sounds like your pot is (on more accurately the interaction of the pot with your case) is the culprit. connecting the case near the pot to PGND with a resistor might just do the trick.
Cheers!
Russ
Congrats!
Not much time to post, busy night, but here is my take on your humm.
It sounds like your pot is (on more accurately the interaction of the pot with your case) is the culprit. connecting the case near the pot to PGND with a resistor might just do the trick.
Cheers!
Russ
Member
Joined 2003
Member
Joined 2003
You are correct though, it is the chassis. Just touching the chassis with my finger decreases the hum. Glad to have that cleared up 🙂
cool light
I have ordered the kit and am now waiting. In the meanwhile I will get the chasis ready. The trans. is from a Kenwood center tapped giving 25+25 ac,when rectified gives me 35+35 dc. Also this trans has a 7vac-12 volt dc which I will run this fan from. This fan has 4 blue led's; It will also serve as my power on indicator.It's a cooler master for a computer. 3.25X3.25X1"deep.It is really quiet with a gentle air flow.What I have to decide is where to put it[front or back]?Hope there will be no added noise from this unit.
happy thursday,
doggy 🙂
I have ordered the kit and am now waiting. In the meanwhile I will get the chasis ready. The trans. is from a Kenwood center tapped giving 25+25 ac,when rectified gives me 35+35 dc. Also this trans has a 7vac-12 volt dc which I will run this fan from. This fan has 4 blue led's; It will also serve as my power on indicator.It's a cooler master for a computer. 3.25X3.25X1"deep.It is really quiet with a gentle air flow.What I have to decide is where to put it[front or back]?Hope there will be no added noise from this unit.
happy thursday,
doggy 🙂
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Plitron toroids are in
Finally got my Plitron toroids. Took about a month. Very nice looking encased in black tape. It has a nice rubber mat attached to the bottom to provide some dampening. Certainly their is the apperance of high quality. We'll see if their sonics are as good as I'm hoping.
My par-metal chassis though came in and is HUGE. Maybe I need to plan a preamp stage in front of the Mauro amp. I am buiding a stereo Rev. A so far.
Anyone think a tubed preamp section is crazy? I think turning this into a tubed hybrid would be interesting......
Maybe I just need a smaller chassis and a nice attenuator???
Finally got my Plitron toroids. Took about a month. Very nice looking encased in black tape. It has a nice rubber mat attached to the bottom to provide some dampening. Certainly their is the apperance of high quality. We'll see if their sonics are as good as I'm hoping.
My par-metal chassis though came in and is HUGE. Maybe I need to plan a preamp stage in front of the Mauro amp. I am buiding a stereo Rev. A so far.
Anyone think a tubed preamp section is crazy? I think turning this into a tubed hybrid would be interesting......
Maybe I just need a smaller chassis and a nice attenuator???
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Tommytube, I heard a chipamp thru my valve pre for the first time today. I tried it with and without the pre in the path, and veryone preferred it with the valve pre in. So to my ears I say go for it. I cant see how adding a valve pre can be be bad. Enjoy
Nigel
Nigel
I cannot comment on this
My system has a solid state buffer in a seperate preamp. Always used in with the My_Reference. Matched fine with Rev A and C.
Cannot imagine having a preamp with gain will hurt the sound much. If your speakers are low sensitivity, the gain will come in handy.
George
My system has a solid state buffer in a seperate preamp. Always used in with the My_Reference. Matched fine with Rev A and C.
Cannot imagine having a preamp with gain will hurt the sound much. If your speakers are low sensitivity, the gain will come in handy.
George
I've ordered a kit and would like to get a little shopping list ready. 25V secondaries are prefered but I have a 300VA with 22V secondaries available. Use that or get one with 25V secondaries, or get 2x 25V, 160VA?
Thanks for all the effort fellas, much appreciated. Missed out on the first round ******ed if I was missing out on this round 😉
Cheers
That word is blanked out... huh... it's not a profanity 🙄
Thanks for all the effort fellas, much appreciated. Missed out on the first round ******ed if I was missing out on this round 😉
Cheers
That word is blanked out... huh... it's not a profanity 🙄
lazyfly said:I've ordered a kit and would like to get a little shopping list ready. 25V secondaries are prefered but I have a 300VA with 22V secondaries available. Use that or get one with 25V secondaries, or get 2x 25V, 160VA?
Thanks for all the effort fellas, much appreciated. Missed out on the first round ******ed if I was missing out on this round 😉
Cheers
That word is blanked out... huh... it's not a profanity 🙄
Hi lazyfly,
While 25V secondaries likely will not cause any problem at all, 24V is actually what is called for. 22V will also work just fine, in fact I have use 21V dual secondaries with good results, the only down side to going that low is headroom, an amp with 21V secondaries will run out of steam and start clipping before an amp with 24V secondaries.
Your dual 22V 300VA is just fine for two channels. If I were you I would probably use that.
Cheers!
Russ
Good morning fellow members,
I have 2 chipamps one with a Plitron trafo. and the other a Hammond. plitron is pricier but has a reputation for quality, they look well made with the potted center. Hammond is also very good,is heavier built and readily available. Yes I had to wait for the plitron also, while they made it! I like them both but I really havn't a-b'd them in the same circuit.
A tube preamp is neat, I have a Bottlehead Foreplay 12au7 which is a kit. What I don't have is solid state pre; I will have to look at the Freebird.
Cheers
doggy🙂
I have 2 chipamps one with a Plitron trafo. and the other a Hammond. plitron is pricier but has a reputation for quality, they look well made with the potted center. Hammond is also very good,is heavier built and readily available. Yes I had to wait for the plitron also, while they made it! I like them both but I really havn't a-b'd them in the same circuit.
A tube preamp is neat, I have a Bottlehead Foreplay 12au7 which is a kit. What I don't have is solid state pre; I will have to look at the Freebird.
Cheers
doggy🙂
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That's why we decided to start up the web site, so no one would miss the round. We hope to keep them stocked rather than leave people out. It requires more upfront capitol, but I think it works out better for everyone in the end.
You might want to hold out for the new pre Russ is working on. He clearly prefers it over the freebird. We're hoping to get the kit going very soon on it.
How about... :-?
Hi everybody,
I was thinking about the case for the "my_ref" I'm gonna build from Brian's kit, and had the idea of building a home made case using two heat sinks of the right size as side walls.
i.e., something like this (view from top):
What do you think about it?
Brian, are there any chance to get properly sized (and reasonably cheap!) heat sinks together with the kit?
Hi everybody,
I was thinking about the case for the "my_ref" I'm gonna build from Brian's kit, and had the idea of building a home made case using two heat sinks of the right size as side walls.
i.e., something like this (view from top):
Code:
rear panel
==|-------------------------------------------------|==
==| |==
==| |* P *| |* P *| |==
==| |* C *| ---- ---- |* C *| |==
==| |* B *| / \ / \ |* B *| |==
==| | TA | | TA | |==
==| \ / \ / |==
==| ---- ---- |==
==|-------------------------------------------------|==
front panel
"==|" and "|==" represents the heat sinks used as side plates.What do you think about it?
Brian, are there any chance to get properly sized (and reasonably cheap!) heat sinks together with the kit?