I'm pretty sure I have enough, Do, so all is clear for a mail out first thing next week.
I will then be left with about 4 boards, which is probably JUST enough!!
I'm very pleased you are liking what you are hearing.......
Hearing is believing in this hobby!!
Cheers,
Hugh
I will then be left with about 4 boards, which is probably JUST enough!!
I'm very pleased you are liking what you are hearing.......
Hearing is believing in this hobby!!
Cheers,
Hugh
I was still getting some hum and mechanical noises from the 300 VA transformer. The noise didn't bother me too much while music was playing, but I knew I had to do something to eliminate it so that the amp could sound its best. While cleaning out my storage area I found a 160 VA toroid (115: 24+24) that I had misplaced and remembered that I had an additional identical transformer in another project that I wasn't using. So I duly swapped the transformers and now there is no hum or buzz.
Interestingly, I checked the operating voltages and the offset settled back to exactly 0 volts again. No pot adjustments were needed.
Without the the hum and buzz, the amp is very enjoyable to listen to and really seems to suit the Tannoy reds.
ray
Interestingly, I checked the operating voltages and the offset settled back to exactly 0 volts again. No pot adjustments were needed.
Without the the hum and buzz, the amp is very enjoyable to listen to and really seems to suit the Tannoy reds.
ray
Auricap sale 40% off
For those wanting to buy Auricap for the amp, head to partsconnexion... They have a 40% off sale!
Yeah!
Do
For those wanting to buy Auricap for the amp, head to partsconnexion... They have a 40% off sale!
Yeah!
Do
So far the amps...
Hi Hugh,
I've been putting some 20+ hours of background music on the amps and I've been listening for a few hours putting some really good recordings
Nah Youn Sun (same girl, voyage)
Miles Davis (blue train)
Diana Krall (the girl in the other room)
Anne Bisson (blue mind)
etc...
I have MANY amps I have build in the past and current and only those I really love make it in a nice chassis. The others, still worthy are on a plywood board and usually stay this way.
From what I've heard so far, I am extremely pleased with the sound, so much that I've decided to build a chassis for it.
I will write a review later on but for now will concentrate on the design of the chassis. I usually put in lots of money in custom chassis that I build using lots of Front Panel Express work for the backplate and frontplate...
So because of costs involved, I'm giving my place for the three boards in group buy 3. This is a little awkward since I'm the one who pushed for GB 3...
So, if there are any takers, you can take them.
Hugh, fear not, if no one takes them, I will at least grad two of them since I believe 1000% they are worth it and the PCB quality is unmatched!
So guy's, don't fear, these amps sound freaaaaakiiiing AMAZING!!!
Let me know if you're interested in three boards. In a week or two, if no one has taken them, like I said, I will keep two of them and build a bi-amp setup...
Now I'm putting aside my preamp project and building a chassis for the FetZilla!!! Yeah!
Do
Hi Hugh,
I've been putting some 20+ hours of background music on the amps and I've been listening for a few hours putting some really good recordings
Nah Youn Sun (same girl, voyage)
Miles Davis (blue train)
Diana Krall (the girl in the other room)
Anne Bisson (blue mind)
etc...
I have MANY amps I have build in the past and current and only those I really love make it in a nice chassis. The others, still worthy are on a plywood board and usually stay this way.
From what I've heard so far, I am extremely pleased with the sound, so much that I've decided to build a chassis for it.
I will write a review later on but for now will concentrate on the design of the chassis. I usually put in lots of money in custom chassis that I build using lots of Front Panel Express work for the backplate and frontplate...
So because of costs involved, I'm giving my place for the three boards in group buy 3. This is a little awkward since I'm the one who pushed for GB 3...
So, if there are any takers, you can take them.
Hugh, fear not, if no one takes them, I will at least grad two of them since I believe 1000% they are worth it and the PCB quality is unmatched!
So guy's, don't fear, these amps sound freaaaaakiiiing AMAZING!!!
Let me know if you're interested in three boards. In a week or two, if no one has taken them, like I said, I will keep two of them and build a bi-amp setup...
Now I'm putting aside my preamp project and building a chassis for the FetZilla!!! Yeah!
Do
Last edited:
Do,
That would be three more boards for me, actually, so my sincere thanks.
Thank you for your impressions, I'm very pleased you posted them. To win a place amongst your chassis-ed amps is a rare privilege!
As before, credit to Lineup for the topology, Greg and Mike for the design, my part was small.
I expect that in about three months when people chime in with their listening impressions that this will be ripe for yet another Group Buy. (HINT: please post your impressions!!) Then I will crank up another pcb order for a further 100 pcbs.
In the meantime, I will post out these latest orders next week, and call now for money to be paid to me at aspen01 -at- optushome.com.au.
I will start a third thread today. I will ask that all who asked for more boards RECONFIRM THEIR ORDER on the GB III thread.
Ciao,
Hugh
That would be three more boards for me, actually, so my sincere thanks.
Thank you for your impressions, I'm very pleased you posted them. To win a place amongst your chassis-ed amps is a rare privilege!
As before, credit to Lineup for the topology, Greg and Mike for the design, my part was small.
I expect that in about three months when people chime in with their listening impressions that this will be ripe for yet another Group Buy. (HINT: please post your impressions!!) Then I will crank up another pcb order for a further 100 pcbs.
In the meantime, I will post out these latest orders next week, and call now for money to be paid to me at aspen01 -at- optushome.com.au.
I will start a third thread today. I will ask that all who asked for more boards RECONFIRM THEIR ORDER on the GB III thread.
Ciao,
Hugh
I guess I must have been smokin' some funny stuff...
blue train is from Coltrane... I meant kind of blue from Miles Davis...!
I will certainly be part of the next GB in a few months. I'll go for bi-amp, build a second identical chassis once I'm done with the first one.
Thanks to all the great minds that engineered, designed this great amp!
Do
blue train is from Coltrane... I meant kind of blue from Miles Davis...!
I will certainly be part of the next GB in a few months. I'll go for bi-amp, build a second identical chassis once I'm done with the first one.
Thanks to all the great minds that engineered, designed this great amp!
Do
Hi Hugh,
I would like to order two boards including parts. It looks like I might have missed this round but wanted to let you know there's still more people who are keen!
Thanks,
Shads
I would like to order two boards including parts. It looks like I might have missed this round but wanted to let you know there's still more people who are keen!
Thanks,
Shads
NO more orders at this stage please guys.
GB #3 is now fully subscribed, but if interest continues to mount I will open GB #4 in a few months.
Cheers,
Hugh
GB #3 is now fully subscribed, but if interest continues to mount I will open GB #4 in a few months.
Cheers,
Hugh
Aspen Fetzilla?
hi hugh.. as i would not rather not wait a few months to start building this amp can you get me the schematic this pcb is based on? I checked out lineup's fetzilla thread and can't tell which fetzilla version this is.
Great work btw.. two terms come to mind: prolific and persistence.
hi hugh.. as i would not rather not wait a few months to start building this amp can you get me the schematic this pcb is based on? I checked out lineup's fetzilla thread and can't tell which fetzilla version this is.
Great work btw.. two terms come to mind: prolific and persistence.
FetZilla PS and Amp Schematic
Woody,
Many thanks!
WLewis,
That's the one, Woody has it nailed. This is it. You will find ALL documentation in the thread, I think it's Post #59.
Hugh
Woody,
Many thanks!
WLewis,
That's the one, Woody has it nailed. This is it. You will find ALL documentation in the thread, I think it's Post #59.
Hugh
Ya know Andrew , i was intending to suggest the same thing last nite , but after scrounging those up and uploading , I forgot to say something .
i just posted a new thread with all the documentation that i've collected . maybe sticky it .
cheers Woody
i just posted a new thread with all the documentation that i've collected . maybe sticky it .
cheers Woody
Hi All,
I have yet to start collecting parts for this amp, but I am working on chassis possibilities and I was wondering if there is any reason why 2 Fetzilla amps couldn't be used in balanced mode.
Can someone shed some light on this for me please?
Many thanks,
Tani.
I have yet to start collecting parts for this amp, but I am working on chassis possibilities and I was wondering if there is any reason why 2 Fetzilla amps couldn't be used in balanced mode.
Can someone shed some light on this for me please?
Many thanks,
Tani.
Tani,
Do you mean balanced input, or bridged output?
If the former, you would need either additional input stage electronics OR a balanced line transformer, the best option.
If the latter, you would need to double the output stage count, two pairs of latfets rather than one, so that the bridged amp could handle the doubled current flow and to avoid degradation of the output impedance, important to damping.
Hope this answers your question,
Hugh
Do you mean balanced input, or bridged output?
If the former, you would need either additional input stage electronics OR a balanced line transformer, the best option.
If the latter, you would need to double the output stage count, two pairs of latfets rather than one, so that the bridged amp could handle the doubled current flow and to avoid degradation of the output impedance, important to damping.
Hope this answers your question,
Hugh
Hi Hugh,
I'm probably using the wrong terminology, but I meant feeding each phase of a balanced input into separated amps, driving either end of the load - as a bridged output would. I thought that this was referred to as balanced operation.
Do the amps each see a more difficult load if this approach is used?
Thanks for the help.
I'm probably using the wrong terminology, but I meant feeding each phase of a balanced input into separated amps, driving either end of the load - as a bridged output would. I thought that this was referred to as balanced operation.
Do the amps each see a more difficult load if this approach is used?
Thanks for the help.
Hi Hugh,
My first incompleted build on one channge first, I will start adding the transistors, the mosfet and the C1 during the weekend. I will post my BOM for the parts that I have selected.
Best regards
My first incompleted build on one channge first, I will start adding the transistors, the mosfet and the C1 during the weekend. I will post my BOM for the parts that I have selected.
Best regards
Hi Syklab,
Nice build, neat and tidy, like the output source resistors!!
You are wisely leaving the 2SK170 and DN2530 until last....... good man!
Tani,
Balanced is where you have a three wire input, a Cannon XLR plug, where the two 'hot' inputs are in antiphase, and the third wire is a ground. This is widely used in proaudio because it's highly immune to noise, but only occasionally in domestic hifi. Your application is called 'bridged', but it does indeed produce a balanced, viz 'antiphase', output, which then drives from opposite ends of the speaker driver.
Bridged means that each amp sees half the load; so an amp designed here for 8R operation becomes two amps that each see 4R. This is the reason the output stage must be beefed up. It also means that even order distortion from each amp is 'balanced', that is, cancelled, and this in turn means the distortion spectrum is reduced, good for THD, but those distortions left are predominantly ODD order, which sound quite different to the FetZilla acting as a single amp.
I do not endorse this approach, because it undoes much of the careful distortion profiling designed into this amplifier, changing its sound drastically, in my opinion for the worse.
Cheers to you both!!
Hugh
Nice build, neat and tidy, like the output source resistors!!
You are wisely leaving the 2SK170 and DN2530 until last....... good man!
Tani,
Balanced is where you have a three wire input, a Cannon XLR plug, where the two 'hot' inputs are in antiphase, and the third wire is a ground. This is widely used in proaudio because it's highly immune to noise, but only occasionally in domestic hifi. Your application is called 'bridged', but it does indeed produce a balanced, viz 'antiphase', output, which then drives from opposite ends of the speaker driver.
Bridged means that each amp sees half the load; so an amp designed here for 8R operation becomes two amps that each see 4R. This is the reason the output stage must be beefed up. It also means that even order distortion from each amp is 'balanced', that is, cancelled, and this in turn means the distortion spectrum is reduced, good for THD, but those distortions left are predominantly ODD order, which sound quite different to the FetZilla acting as a single amp.
I do not endorse this approach, because it undoes much of the careful distortion profiling designed into this amplifier, changing its sound drastically, in my opinion for the worse.
Cheers to you both!!
Hugh
Last edited:
- Status
- Not open for further replies.