SY/Pete Millett Crossover

SY · 19th February 2010, 08:10 PM

I wanted to split some of the discussion off from the Pete Millett crossover PCB thread, but figured it would be easier to start a new one.

Whereas... Pete has never really been happy with his Sallen-Key crossover.
Whereas... I have been more than delighted with my Acheron, a gyrator-based design.
Whereas... I have recently joined Pete in the Great State of Texas.
Whereas... Pete and I are looking for an excuse to get together and do some drinking,

Be it now announced that, if there's sufficient interest, we will be collaborating on a project. Pete has left the grunt design work to me; he'll do the PCB design. We're strongly leaning toward replacing the op-amp gyrators with pentodes, but using the basic cathode follower and servo circuitry from my original design.

Here's the options: this will be a second-order circuit. Most likely to get done quickly is a two way, with the bass section being handled by solid state and the upper section being done with tubes. Sections could be cascaded to give 4th order. If people want the bass to be done with tubes and/or a three-way, that could take a bit longer (my design and bench time are sadly limited these days), but if that's what it will take, that's what it will take. regulated supplies, of course. And single ended, though the enterprising could certainly add input and/or output transformers.

So... is there interest enough to inspire us to put the time in, start the breadboarding, and pop a few Belgian ales?

SGregory · 19th February 2010, 08:14 PM

I am definatley in.

vanofmonks · 19th February 2010, 08:19 PM

I too am definitely in. Looking forward to it.

planet10 · 19th February 2010, 08:38 PM

Sounds like a plan.

dave

rotaspec · 19th February 2010, 08:54 PM

Sounds interesting. I've been looking at triode-based designs, but pentodes could be a possibility. I'm building an Aikido linestage, and there's room on the chassis for a few more tubes. Got any particular bottles in mind? Please don't say EF86, they are like Platinum out here (on the very rare occasion they come up for sale)

Consider the rest of the world as watching with interest, and may only have access to the likes of Russian tubes for example.

Gary

SY · 19th February 2010, 08:58 PM

The pentode is just for the gyrator- the signal handling will be done by a triode, most likely an ECC88 or one of that family. The pentodes will NOT be some collector's item- more likely, they will be some orphan American type that you can get for a buck.

kenpeter · 19th February 2010, 09:07 PM

ECC88 cascode?

SY · 19th February 2010, 09:09 PM

Nope, just a plain vanilla, other than the output servo to eliminate the output coupling cap. See the Heretical article on my website for the performance.

d to the g · 19th February 2010, 09:28 PM

IN opamp gyrators would be fine with me. still more linear than a big choke.

bigjppop · 19th February 2010, 09:28 PM

Always interested in seeing what the "big boys" are building! Tell us more!

19th February 2010, 08:10 PM	#1
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	SY/Pete Millett Crossover I wanted to split some of the discussion off from the Pete Millett crossover PCB thread, but figured it would be easier to start a new one. Whereas... Pete has never really been happy with his Sallen-Key crossover. Whereas... I have been more than delighted with my Acheron, a gyrator-based design. Whereas... I have recently joined Pete in the Great State of Texas. Whereas... Pete and I are looking for an excuse to get together and do some drinking, Be it now announced that, if there's sufficient interest, we will be collaborating on a project. Pete has left the grunt design work to me; he'll do the PCB design. We're strongly leaning toward replacing the op-amp gyrators with pentodes, but using the basic cathode follower and servo circuitry from my original design. Here's the options: this will be a second-order circuit. Most likely to get done quickly is a two way, with the bass section being handled by solid state and the upper section being done with tubes. Sections could be cascaded to give 4th order. If people want the bass to be done with tubes and/or a three-way, that could take a bit longer (my design and bench time are sadly limited these days), but if that's what it will take, that's what it will take. regulated supplies, of course. And single ended, though the enterprising could certainly add input and/or output transformers. So... is there interest enough to inspire us to put the time in, start the breadboarding, and pop a few Belgian ales? __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

19th February 2010, 08:14 PM	#2
SGregory Tubie Noobie diyAudio Member Join Date: Apr 2003 Location: Southern Tier NY	I am definatley in. __________________ Living Life Doing the Waltz in 4/4 meter.

19th February 2010, 08:38 PM	#4
planet10 frugal-phile(tm) diyAudio Moderator Join Date: Oct 2001 Location: Victoria, BC, NA, Sol III Blog Entries: 4	Sounds like a plan. dave __________________ community sites t-linespeakers.org, frugal-horn.com ........ commercial site planet10-HiFi p10-hifi forum here at diyA

19th February 2010, 08:58 PM	#6
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	The pentode is just for the gyrator- the signal handling will be done by a triode, most likely an ECC88 or one of that family. The pentodes will NOT be some collector's item- more likely, they will be some orphan American type that you can get for a buck. __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

19th February 2010, 09:09 PM	#8
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	Nope, just a plain vanilla, other than the output servo to eliminate the output coupling cap. See the Heretical article on my website for the performance. __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

19th February 2010, 08:19 PM	#3
vanofmonks diyAudio Member Join Date: May 2006	I too am definitely in. Looking forward to it.

19th February 2010, 08:54 PM	#5
rotaspec diyAudio Member Join Date: Nov 2007	Sounds interesting. I've been looking at triode-based designs, but pentodes could be a possibility. I'm building an Aikido linestage, and there's room on the chassis for a few more tubes. Got any particular bottles in mind? Please don't say EF86, they are like Platinum out here (on the very rare occasion they come up for sale) Consider the rest of the world as watching with interest, and may only have access to the likes of Russian tubes for example. Gary

19th February 2010, 09:07 PM	#7
kenpeter diyAudio Member Join Date: Nov 2007 Location: Dallas	ECC88 cascode?

19th February 2010, 09:28 PM	#9
d to the g diyAudio Member Join Date: Aug 2006 Location: minimalopolis	IN opamp gyrators would be fine with me. still more linear than a big choke.

19th February 2010, 09:28 PM	#10
bigjppop diyAudio Member Join Date: Jun 2009 Location: Berlin	Always interested in seeing what the "big boys" are building! Tell us more!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Group buy pulse check for Pete Millett tube crossover PCB	leadbelly	Tubes / Valves	82	24th February 2010 09:32 PM
Anyone Interested in Pete Millett Hybrid Amp PCB's?	Geek	Tubes / Valves	3	2nd November 2008 11:56 PM
Last Pair of Pete Millett Universal Driver PCB's	Geek	Swap Meet	2	25th March 2008 09:03 PM
Pete Millett Universal Driver PCB's	Geek	Swap Meet	3	3rd September 2007 07:36 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read