Classic Aleph Amplifier for Modern UMS Chassis - Group Buy
- By rhthatcher
- Group Buys
- 109 Replies
Attachments
RCA 5879 Phono Preamp
- By drteming
- Tubes / Valves
- 25 Replies
Does anyone have any experience with the 5879 phono preamp in the "RCA High-Fidelity Amplifier Circuits" booklet? The schematic is as follows.
I have looked pretty extensively and only found a mention or 2 on the web, but nothing significant. I'm looking to build one as I have a bunch of the 5879 tubes and have used them in guitar and audio amps with good success. I have an entry level (at best) turntable with the Audio Technical AT-3600L cartridge, and I'm totally happy with the sound. That either makes me a noob or a philistine, or maybe both. Anyway, I proposed some changes as follows.
1) Grid stoppers on all sections
2) 5879 screen bypass capacitor to cathode instead of ground
3) Instead of a 7025/12AX7, a 6AV6 and a 6C4 cathode follower (it'll be driving a 100k load). If the gain is too high, a 6AT6 can be swapped in.
4) Larger cathode bypass capacitors, because it's much cheaper in 2022
Also, how much of a difference would there be if I used a 22nF and 4.7nf caps for C5 and C6?
Any comments or insights will be greatly appreciated.
I have looked pretty extensively and only found a mention or 2 on the web, but nothing significant. I'm looking to build one as I have a bunch of the 5879 tubes and have used them in guitar and audio amps with good success. I have an entry level (at best) turntable with the Audio Technical AT-3600L cartridge, and I'm totally happy with the sound. That either makes me a noob or a philistine, or maybe both. Anyway, I proposed some changes as follows.
1) Grid stoppers on all sections
2) 5879 screen bypass capacitor to cathode instead of ground
3) Instead of a 7025/12AX7, a 6AV6 and a 6C4 cathode follower (it'll be driving a 100k load). If the gain is too high, a 6AT6 can be swapped in.
4) Larger cathode bypass capacitors, because it's much cheaper in 2022
Also, how much of a difference would there be if I used a 22nF and 4.7nf caps for C5 and C6?
Any comments or insights will be greatly appreciated.
DAC ES9038 PRO GR 2
- By quanghao
- Group Buys
- 267 Replies
Attachments
-
Manual Kit ES9038PRO DAC+ Controle2.jpg -
Structural-design-ES9038pro.jpg -
Structural-Supply-ES9038pro.jpg -
Manual Kit ES9038PRO DAC+ Controle7.jpg -
Manual Kit ES9038PRO DAC+ Controle5.jpg -
Manual Kit ES9038PRO DAC+ Controle6.jpg -
Manual Kit ES9038PRO DAC+ Controle8.jpg -
Manual Kit ES9038PRO DAC+ Controle9.jpg -
Manual Kit ES9038PRO DAC+ Controle10.jpg -
Manual Kit ES9038PRO DAC+ Controle11.jpg
Restored, A.N.T. Modified & Fine Tuned Sony TC-K850ES 3 Head Cassette Deck Quartz Locked Direct Drive
- By PaulRobert
- Analogue Source
- 30 Replies
Hello
I Had this non-working Sony TC-K850ES cassette deck in my shop for some time. A customer who was interested in this model messaged me to buy this. I restored the deck with original genuine Sony Pinch Rollers, Belts and an assortment of gears for the mode encoder mechanics. Replaced the SMD capacitors on the direct drive board and replaced the Standard capacitors on the motor controller board with Nichicon Fine Gold. After restoration the deck records and plays back as intended. The head was in good condition despite it being permalloy material. The deck has Nichicon muse in the recording and playback chains. A solid built machine
I noticed the deck was using some outdated op amps and a low grade 4066 chipset which downgraded the sound quality potential. I went ahead and replaced all op amps in the circuit with Texas Instruments NE5532P and the 4066 upgraded to the ANT4066B. A significant improvement now in recording and playback. Much better than the original state
I added the original advertising stickers specific to this deck as a finishing touch
The deck is now complete and with the new owner.
I Had this non-working Sony TC-K850ES cassette deck in my shop for some time. A customer who was interested in this model messaged me to buy this. I restored the deck with original genuine Sony Pinch Rollers, Belts and an assortment of gears for the mode encoder mechanics. Replaced the SMD capacitors on the direct drive board and replaced the Standard capacitors on the motor controller board with Nichicon Fine Gold. After restoration the deck records and plays back as intended. The head was in good condition despite it being permalloy material. The deck has Nichicon muse in the recording and playback chains. A solid built machine
I noticed the deck was using some outdated op amps and a low grade 4066 chipset which downgraded the sound quality potential. I went ahead and replaced all op amps in the circuit with Texas Instruments NE5532P and the 4066 upgraded to the ANT4066B. A significant improvement now in recording and playback. Much better than the original state
I added the original advertising stickers specific to this deck as a finishing touch
The deck is now complete and with the new owner.
Magnepan 3.7i - Convert crossover to parallel
- Planars & Exotics
- 35 Replies
I have a pair of magi 3.7i and would like to convert the crossover from serial to parallel.
So I can bi-amp them and play around with better parts.
From the schematic it looks like, and I am guessing 😊
12 db on the tweeter
6 db band pass on the midrange
6 db on the woofer
Am I right?
Found the schematic here http://www.integracoustics.com/MUG/MUG/tweaks/neolith/
I don't know where I can find neolith so I hope it's okay to use his material
So I can bi-amp them and play around with better parts.
From the schematic it looks like, and I am guessing 😊
12 db on the tweeter
6 db band pass on the midrange
6 db on the woofer
Am I right?
Found the schematic here http://www.integracoustics.com/MUG/MUG/tweaks/neolith/
I don't know where I can find neolith so I hope it's okay to use his material
First Watt F3 Project
I have far too many projects either on the go or waiting to be picked up so I'm going to cull some.
A set of PCBs and matched LD1014D FETS, courtesy of Nelson Pass, for a clone of the First Watt F3 amplifier. Purched via a GB here on DIY Audio, details here;
https://www.diyaudio.com/community/threads/f3-clone-board-set-group-buy.373750/
I have:
2 x amplifier boards
2 x output boards
2 x PS boards
2 x LED boards
2 x XRK mpunting boards for LD1014D devices
The LD1014D devices were a gift from NP to the DIY audio community and I'm not looking to make money on them so the cost is just to recover my investment in the PCBs - looking for £25 plus shipping at cost.
A set of PCBs and matched LD1014D FETS, courtesy of Nelson Pass, for a clone of the First Watt F3 amplifier. Purched via a GB here on DIY Audio, details here;
https://www.diyaudio.com/community/threads/f3-clone-board-set-group-buy.373750/
I have:
2 x amplifier boards
2 x output boards
2 x PS boards
2 x LED boards
2 x XRK mpunting boards for LD1014D devices
The LD1014D devices were a gift from NP to the DIY audio community and I'm not looking to make money on them so the cost is just to recover my investment in the PCBs - looking for £25 plus shipping at cost.
DAC: CS4398 with CS8416+CM102s
- Digital Line Level
- 141 Replies
As title says I did buy this eBay DAC board and associated enclosure from along1986090. Used my transformers.
CS4398 with CS8416+CM102s, provides coaxial SPDIF and USB inputs.
First impressions:
Enclosure definitelly well done, with (almost) all necessary hardware, holes in exact locations to match the board. Kind of long (10", plus 1/4" front aluminium plate), I guess it can be used to add a dedicated headphones amp.
I did buy the pre-solderd board. Inspected with the magnifier glass showed an OK grade of soldering. PCB is in filled ground technique and parts are like shown in the picture.
Initial tests had a sligtly distorted signal and analized with my E-MU1820m showed a really bad signal. I did replace the 5532 that was on board with LM4562 that I hade around and everything started to look better. I suspect that the 5532 was either a fake or a damaged exemplar. There is no capacitor or resitors on OpAmp outputs, so it is easy to be damaged.
At -2dB looks decent. The output stage overloads my ADC input at higher than -2dB (all the other DAC's that I tested didn't manage to do that).
The output stage is not done per recomended schematics in the datasheet.
USB input:
CM102 locks only onto 16bit/48kHz signals. 16bit/44.1kHz is not supported in Windows7 mixer (WASAPI).
If looses the connection with the PC, static noise is outputted till the next power off/on cycle. The automatic switching could be done better I guess...
Altough in Win 7 there is no need for drivers, here is a package that provides a little more that basic USB. This driver looks like it does the resampling to 48kHz automatically.
Coax SPDIF:
Locks on 44.1-96kHz, 16 or 24 bit. I don't have a SPDIF source capable of 192kHz to fully test the CS8416.
Using Foobar with resampling to 48kHz would allow USB connection to work at any rate, but I do prefer the coax.
All in all, sounds decent, especially for the price. THD+N with LM4562 is at -94dB. OpAmp upgrade is strongly recomended and looks like some of the AC grid noise could be reduced by better filtering.
Direct coupling of the outputs leaves some higher levels of 10Hz noise creep into the output chain as seen in the coax graph (at USB I forgot to extend the range below 20Hz).
The seller give the schematics (at my request).
CS4398 with CS8416+CM102s, provides coaxial SPDIF and USB inputs.
First impressions:
Enclosure definitelly well done, with (almost) all necessary hardware, holes in exact locations to match the board. Kind of long (10", plus 1/4" front aluminium plate), I guess it can be used to add a dedicated headphones amp.
I did buy the pre-solderd board. Inspected with the magnifier glass showed an OK grade of soldering. PCB is in filled ground technique and parts are like shown in the picture.
Initial tests had a sligtly distorted signal and analized with my E-MU1820m showed a really bad signal. I did replace the 5532 that was on board with LM4562 that I hade around and everything started to look better. I suspect that the 5532 was either a fake or a damaged exemplar. There is no capacitor or resitors on OpAmp outputs, so it is easy to be damaged.
At -2dB looks decent. The output stage overloads my ADC input at higher than -2dB (all the other DAC's that I tested didn't manage to do that).
The output stage is not done per recomended schematics in the datasheet.
USB input:
CM102 locks only onto 16bit/48kHz signals. 16bit/44.1kHz is not supported in Windows7 mixer (WASAPI).
If looses the connection with the PC, static noise is outputted till the next power off/on cycle. The automatic switching could be done better I guess...
Altough in Win 7 there is no need for drivers, here is a package that provides a little more that basic USB. This driver looks like it does the resampling to 48kHz automatically.
Coax SPDIF:
Locks on 44.1-96kHz, 16 or 24 bit. I don't have a SPDIF source capable of 192kHz to fully test the CS8416.
Using Foobar with resampling to 48kHz would allow USB connection to work at any rate, but I do prefer the coax.
All in all, sounds decent, especially for the price. THD+N with LM4562 is at -94dB. OpAmp upgrade is strongly recomended and looks like some of the AC grid noise could be reduced by better filtering.
Direct coupling of the outputs leaves some higher levels of 10Hz noise creep into the output chain as seen in the coax graph (at USB I forgot to extend the range below 20Hz).
The seller give the schematics (at my request).
Attachments
BMR Group Delay
- By Lawnboy
- Full Range
- 8 Replies
Hello everyone, I was watching Erins Audio Corner a few days ago with Dr Geddes as a guest and he briefly mentioned group delay and used BMR drivers as an example, then said no more on the subject. I became very interested in the tectonic 2” BMR after reading Erins shining review. It seems like the ideal driver for my tastes as I can’t really hear sparkle (I’m 41 as of today) and the frequency and polar response are stand up, which is much more important to me.
But, I worry now about group delay distortion smearing in the time realm. I imagine that the sections resonating semi independently might take enough time in relation to the higher frequency cycles to matter where we’re very sensitive. Would anyone care to share their understanding of this?
Some might be tempted to point out that if I have to ask then I obviously don’t notice it even if it exists and it doesn’t matter then. The thing is years ago I didn’t know about the stereo illusion but now I do, and it matters. There was a time when I didn’t know that my car door speakers were beaming and there was a major problem in the upper midrange response at the listening position, and that most certainly mattered. I wonder if the tradeoff for the wide dispersion is group delay as Mother Nature gives with one hand while taking with the other. Is this concern valid?
I very recently began designing and assembling a small stereo system from the basic components. Kabd amplifier boards, open frame power supply, raw drivers, ect. I chose a two way system with the BMR 2” not because I couldn’t implement a decent three way, but because I felt I didn’t have to with the BMR. If there’s a real problem with the BMR’s I’ll be looking at the RS100 or RS75 and one of the reference tweeters. There’s a chance I’d go for one of the other Dayton 28mm tweeters because of availability. I have some beliefs regarding crossover points that might be too careful but this can wait to be discussed under after the group delay thing has been sorted.
My bookshelves currently have the Tectonic 2”, Anarchy 704, and RSS210 passive radiator on ~60w and 15w respectively. I’m really happy with the result but I want to make sure I’m not missing something that once I perceive it it’ll bug me ferociously. Btw is Erin @bikinpunk here? He’s Erinh on diyma where I’ve basically learned everything I know.
But, I worry now about group delay distortion smearing in the time realm. I imagine that the sections resonating semi independently might take enough time in relation to the higher frequency cycles to matter where we’re very sensitive. Would anyone care to share their understanding of this?
Some might be tempted to point out that if I have to ask then I obviously don’t notice it even if it exists and it doesn’t matter then. The thing is years ago I didn’t know about the stereo illusion but now I do, and it matters. There was a time when I didn’t know that my car door speakers were beaming and there was a major problem in the upper midrange response at the listening position, and that most certainly mattered. I wonder if the tradeoff for the wide dispersion is group delay as Mother Nature gives with one hand while taking with the other. Is this concern valid?
I very recently began designing and assembling a small stereo system from the basic components. Kabd amplifier boards, open frame power supply, raw drivers, ect. I chose a two way system with the BMR 2” not because I couldn’t implement a decent three way, but because I felt I didn’t have to with the BMR. If there’s a real problem with the BMR’s I’ll be looking at the RS100 or RS75 and one of the reference tweeters. There’s a chance I’d go for one of the other Dayton 28mm tweeters because of availability. I have some beliefs regarding crossover points that might be too careful but this can wait to be discussed under after the group delay thing has been sorted.
My bookshelves currently have the Tectonic 2”, Anarchy 704, and RSS210 passive radiator on ~60w and 15w respectively. I’m really happy with the result but I want to make sure I’m not missing something that once I perceive it it’ll bug me ferociously. Btw is Erin @bikinpunk here? He’s Erinh on diyma where I’ve basically learned everything I know.
Soekris dam-1121 + Burson OpAmps + Tentlabs clock
Everything is sold !!
I bought a new streaming amp so I do not need a separate DAC anymore.
For sale a Soekris dam-1121 DAC from 2019 with the latest firmware update installed.
This is the version with 0,02% resistors.
No soldering done, the connectors were used with female (push-on) adapters so the PCB is really like new.
Asking 100 EUR.
From when I was building it with LT3045/3094 voltage regulators:
Some other bits and bytes:
About 12 years ago I modified my CD-player with Burson discrete OpAmps (dual version) and a Tentlabs clock with 16.934 Mhz XO.
These do have soldering marks but are in 100% working order.
I switched to streaming a few years later so these have only been used approx. 3-4 years ?
Asking:
Burson dual OpAmps: 50 EUR
Tentlabs clock incl. XO: 50 EUR
I bought a new streaming amp so I do not need a separate DAC anymore.
For sale a Soekris dam-1121 DAC from 2019 with the latest firmware update installed.
This is the version with 0,02% resistors.
No soldering done, the connectors were used with female (push-on) adapters so the PCB is really like new.
Asking 100 EUR.
From when I was building it with LT3045/3094 voltage regulators:
Some other bits and bytes:
About 12 years ago I modified my CD-player with Burson discrete OpAmps (dual version) and a Tentlabs clock with 16.934 Mhz XO.
These do have soldering marks but are in 100% working order.
I switched to streaming a few years later so these have only been used approx. 3-4 years ?
Asking:
Burson dual OpAmps: 50 EUR
Tentlabs clock incl. XO: 50 EUR
Piano Speaker polars
I have an idea to build a case for a piano controller to convert it into a stand-alone piano.
Multiway speaker drivers would fit very naturally into a piano-ish shape.
So it would look a little like this cosmetic case, except contain speakers and amps.
(Doesn't it just cry out for a woofer to fit in the curve, tweeter just where the treble notes should be?)
It could be built as a sealed box speaker, but a real piano is more like an open backed dipole I suspect.
That would partially null out the bass frequencies in the approximate plane of the cabinet.
Does this actually happen?
I've never jumped up and down at a piano recital to compare the sound. 😉
I am sure the polar response of a real concert piano has been studied, anyone have ideas or references?
David
Multiway speaker drivers would fit very naturally into a piano-ish shape.
So it would look a little like this cosmetic case, except contain speakers and amps.
(Doesn't it just cry out for a woofer to fit in the curve, tweeter just where the treble notes should be?)
It could be built as a sealed box speaker, but a real piano is more like an open backed dipole I suspect.
That would partially null out the bass frequencies in the approximate plane of the cabinet.
Does this actually happen?
I've never jumped up and down at a piano recital to compare the sound. 😉
I am sure the polar response of a real concert piano has been studied, anyone have ideas or references?
David
Purifi’s PTT6.5W04-01A woofer group buy
- By Norman Tracy
- Group Buys
- 162 Replies
Purifi's PTT6.5W04-01A woofer group buy
You are invited to join a North American group buy of the Purifi’s groundbreaking long-stroke ultra-low-distortion PTT6.5W04-01A woofer, and optionally the matching PTT6.5PR-01A Passive Radiator. Owing to Purifi’s policy requiring orders go to a single address this gets complex, thus the long post.
Announcing the Purifi group buy will close January 31, 2020. At that point we will aggregate our funds and place the order with Purifi. Logistics require we place a single order so we will not be able to accommodate stragglers after the cutoff on the 31st. Sorry about that, I am a procrastinator myself but in this case we are early adopters and a decision is required.
Many of us have taken note of Purifi (Purifi Audio), a new research focused company in Denmark founded and staffed by a distinguished group of Hi-Fi industry heavyweights. The team at Purifi (for the roster see About - PURIFI) has extensive experience in the electronics, loudspeaker, and business sides of Hi-Fi. A following post to this thread will include links to both Purifi’s technology white papers and independent testing and listening reviews.
On the loudspeaker side Purifi’s initial offering is the PTT6.5W04-01A 6.5 inch woofer, a design that reduces distortion by tens of dBs while remaining linear to extreme excursion levels. This promises to allow bass depth with low midrange distortion that is normally the providence of large speakers using 12 and 15 inch woofers in jumbo multi-cubic foot boxes to be had from a ½ cubic foot / 15 liter enclosure 2-way system.
Purifi’s PTT6.5W04-01A is manufactured in Denmark. That is a good news bad news situation. Good news is for decades Denmark and Scandinavia have been a primary source of state of the art loudspeaker drivers and with European manufacturing by this team quality is a given. The downside is price, it does cost to manufacture in Europe, in this case $250 to $350 per driver depending on where one falls on the price breaks. So let us band together and save some dollars.
Purifi conducts all of their business in Danish krone, 1 Danish Krone equaling approximately 0.15 United States Dollar. As of this posting date cost in Danish krone and US dollars are as follows. These prices do not include shipping.
PTT6.5W04-01A Woofer Quantity based pricing table
Min__Max__Unit Price DKK__Unit Price USD
1____3_____2,329.00______$349.35
4____5_____2,108.00______$316.20
6____7_____1,871.00______$280.65
8____8+____1,663.00______$249.45
PTT6.5PR-01A Passive Radiator Quantity based pricing table
Min__Max__Unit Price DKK__Unit Price USD
1____3_____844.00________$126.60
4____5_____761.00________$114.15
6____7_____672.00________$100.80
8____8+____593.00________$88.95
Obviously if four or more of us commit to a pair of woofers each we can access the 8 pieces and above price break saving $150 to $200US on a pair. The exact savings depending on shipping costs, which I intend to pass on at cost. There will be no markup on this effort, I am donating my time to encourage fellow early adopters. That time will primarily be breaking the big shipment from Denmark into individual pairs, re-packing, and shipping onto the group members. Alas, to access the 8 and above price the shipment must be to a single address so a second shipment within N. America is required. I do have a commercial shipping address, which gets us a discount from Purifi’s shipping service DHL and avoids porch pirate worries.
Thanks to Purifi’s web store we can see exact cost to land a group buy to USA. The following tables show those costs as of January 2020 with shipping to Oklahoma. The first table for a group order for four of us to get one pair of PTT6.5W04-01A woofers each, eight drivers total. The second table shows the cost to buy a single pair of drivers as a comparison.
PTT6.5W04-01A Web Costing Group Buy
Item_____Quantity___Unit Price DKK__Unit Price USD___Order Price DKK__Order Price USD
PTT6.5-04___8_______1,663.00_______$249.45_________13,304.00______$1,995.60
Shipping____1_______1,312.00_______$196.80__________1,312.00_______$196.80
__________________________________totals__________14,616.00______$2,192.40
Unit cost group buy landed in USA $274.05
Pair cost group buy landed in USA $548.10
PTT6.5W04-01A Web Costing Individual Buy
Item_____Quantity___Unit Price DKK__Unit Price USD___Order Price DKK__Order Price USD
PTT6.5-04__2________2,329.00_______$349.35_________4,658.00________$698.70
Shipping___1__________622.00________$93.30__________622.00_________$93.30
_____________________________________totals_______5,280.00_________$792.00
Unit cost individual’s buy landed in USA $396.00
Pair cost individual’s buy landed in USA $792.00
Bottom line is buying individually a pair cost $792 vs. as a group $548 + Oklahoma to you shipping.
If you want to join this group buy reply to this thread and send me a personal message with contact info. I plan the process to proceed as follows:
1. Recruit enough participants to qualify for quantity 8+ pricing.
2. Close participation in initial group buy.
3. Check costs to buy woofers (and passive radiators if anyone orders those) and shipping costs Denmark to Oklahoma, communicate each individual’s total to participants.
4. Participants pay using PayPal to group buy organizer. Your PayPal receipt will state “Expected delivery time 6 – 8 weeks”, I will try to beat that, most of that will be determined by Purifi’s build time and shipping including clearing USA customs.
5. When all funds arrive order is placed with Purifi. Be aware Purifi states “Note that this product is made-to-order. Expect approximately 4 weeks delivery time.”
6. While Purifi builds and ship woofers group organizer will prepare boxes and packing for shipping leg within North America.
7. When shipment arrives in Oklahoma group organizer will break down into shipments to individual participants, determine cost, and communicate to each participant their North American final leg shipping cost.
8. After participant pays their individual within N. America cost group organizer ships their order.
9. Woofers arrive individual participants’ workshops where they are installed in boxes. Jaws drop, sonic bliss ensues.
Obviously at this level of cost to entry we have a classic case of it is expensive to participate at the cutting edge of technology. I expect the cost to entry will surface individuals with the commitment and means to participate. Given that one should not need to say, yet out of an abundance of caution I will; do not be a wimp! Once you commit do not try and back out! This is not Amazon with free returns, you buy via this group buy and they are yours. If ultimately the sound is not to your liking it is on you to store, scrap, or sell them on. I do not intend to allow that reality to give Purifi a pass on their quality obligation to deliver product as specified to us. What I will not allow is audiophile wimp buyer’s remorse with excuses like “I don’t like how it looks”, “I’ve decided to go a different route and want a refund to help fund that project”, or “upon audition they lack a certain air and “je ne sais quoi” my incredibly refined hearing cannot do without”.
I am excited the Purifi PTT6.5W04-01A is a true breakthrough, something rare in such a mature century old technology. I hope you will join me as one of the first to explore it.
You are invited to join a North American group buy of the Purifi’s groundbreaking long-stroke ultra-low-distortion PTT6.5W04-01A woofer, and optionally the matching PTT6.5PR-01A Passive Radiator. Owing to Purifi’s policy requiring orders go to a single address this gets complex, thus the long post.
Announcing the Purifi group buy will close January 31, 2020. At that point we will aggregate our funds and place the order with Purifi. Logistics require we place a single order so we will not be able to accommodate stragglers after the cutoff on the 31st. Sorry about that, I am a procrastinator myself but in this case we are early adopters and a decision is required.
Many of us have taken note of Purifi (Purifi Audio), a new research focused company in Denmark founded and staffed by a distinguished group of Hi-Fi industry heavyweights. The team at Purifi (for the roster see About - PURIFI) has extensive experience in the electronics, loudspeaker, and business sides of Hi-Fi. A following post to this thread will include links to both Purifi’s technology white papers and independent testing and listening reviews.
On the loudspeaker side Purifi’s initial offering is the PTT6.5W04-01A 6.5 inch woofer, a design that reduces distortion by tens of dBs while remaining linear to extreme excursion levels. This promises to allow bass depth with low midrange distortion that is normally the providence of large speakers using 12 and 15 inch woofers in jumbo multi-cubic foot boxes to be had from a ½ cubic foot / 15 liter enclosure 2-way system.
Purifi’s PTT6.5W04-01A is manufactured in Denmark. That is a good news bad news situation. Good news is for decades Denmark and Scandinavia have been a primary source of state of the art loudspeaker drivers and with European manufacturing by this team quality is a given. The downside is price, it does cost to manufacture in Europe, in this case $250 to $350 per driver depending on where one falls on the price breaks. So let us band together and save some dollars.
Purifi conducts all of their business in Danish krone, 1 Danish Krone equaling approximately 0.15 United States Dollar. As of this posting date cost in Danish krone and US dollars are as follows. These prices do not include shipping.
PTT6.5W04-01A Woofer Quantity based pricing table
Min__Max__Unit Price DKK__Unit Price USD
1____3_____2,329.00______$349.35
4____5_____2,108.00______$316.20
6____7_____1,871.00______$280.65
8____8+____1,663.00______$249.45
PTT6.5PR-01A Passive Radiator Quantity based pricing table
Min__Max__Unit Price DKK__Unit Price USD
1____3_____844.00________$126.60
4____5_____761.00________$114.15
6____7_____672.00________$100.80
8____8+____593.00________$88.95
Obviously if four or more of us commit to a pair of woofers each we can access the 8 pieces and above price break saving $150 to $200US on a pair. The exact savings depending on shipping costs, which I intend to pass on at cost. There will be no markup on this effort, I am donating my time to encourage fellow early adopters. That time will primarily be breaking the big shipment from Denmark into individual pairs, re-packing, and shipping onto the group members. Alas, to access the 8 and above price the shipment must be to a single address so a second shipment within N. America is required. I do have a commercial shipping address, which gets us a discount from Purifi’s shipping service DHL and avoids porch pirate worries.
Thanks to Purifi’s web store we can see exact cost to land a group buy to USA. The following tables show those costs as of January 2020 with shipping to Oklahoma. The first table for a group order for four of us to get one pair of PTT6.5W04-01A woofers each, eight drivers total. The second table shows the cost to buy a single pair of drivers as a comparison.
PTT6.5W04-01A Web Costing Group Buy
Item_____Quantity___Unit Price DKK__Unit Price USD___Order Price DKK__Order Price USD
PTT6.5-04___8_______1,663.00_______$249.45_________13,304.00______$1,995.60
Shipping____1_______1,312.00_______$196.80__________1,312.00_______$196.80
__________________________________totals__________14,616.00______$2,192.40
Unit cost group buy landed in USA $274.05
Pair cost group buy landed in USA $548.10
PTT6.5W04-01A Web Costing Individual Buy
Item_____Quantity___Unit Price DKK__Unit Price USD___Order Price DKK__Order Price USD
PTT6.5-04__2________2,329.00_______$349.35_________4,658.00________$698.70
Shipping___1__________622.00________$93.30__________622.00_________$93.30
_____________________________________totals_______5,280.00_________$792.00
Unit cost individual’s buy landed in USA $396.00
Pair cost individual’s buy landed in USA $792.00
Bottom line is buying individually a pair cost $792 vs. as a group $548 + Oklahoma to you shipping.
If you want to join this group buy reply to this thread and send me a personal message with contact info. I plan the process to proceed as follows:
1. Recruit enough participants to qualify for quantity 8+ pricing.
2. Close participation in initial group buy.
3. Check costs to buy woofers (and passive radiators if anyone orders those) and shipping costs Denmark to Oklahoma, communicate each individual’s total to participants.
4. Participants pay using PayPal to group buy organizer. Your PayPal receipt will state “Expected delivery time 6 – 8 weeks”, I will try to beat that, most of that will be determined by Purifi’s build time and shipping including clearing USA customs.
5. When all funds arrive order is placed with Purifi. Be aware Purifi states “Note that this product is made-to-order. Expect approximately 4 weeks delivery time.”
6. While Purifi builds and ship woofers group organizer will prepare boxes and packing for shipping leg within North America.
7. When shipment arrives in Oklahoma group organizer will break down into shipments to individual participants, determine cost, and communicate to each participant their North American final leg shipping cost.
8. After participant pays their individual within N. America cost group organizer ships their order.
9. Woofers arrive individual participants’ workshops where they are installed in boxes. Jaws drop, sonic bliss ensues.
Obviously at this level of cost to entry we have a classic case of it is expensive to participate at the cutting edge of technology. I expect the cost to entry will surface individuals with the commitment and means to participate. Given that one should not need to say, yet out of an abundance of caution I will; do not be a wimp! Once you commit do not try and back out! This is not Amazon with free returns, you buy via this group buy and they are yours. If ultimately the sound is not to your liking it is on you to store, scrap, or sell them on. I do not intend to allow that reality to give Purifi a pass on their quality obligation to deliver product as specified to us. What I will not allow is audiophile wimp buyer’s remorse with excuses like “I don’t like how it looks”, “I’ve decided to go a different route and want a refund to help fund that project”, or “upon audition they lack a certain air and “je ne sais quoi” my incredibly refined hearing cannot do without”.
I am excited the Purifi PTT6.5W04-01A is a true breakthrough, something rare in such a mature century old technology. I hope you will join me as one of the first to explore it.
Decware DNA Horn
- By xrk971
- Full Range
- 322 Replies
In the Foam Core thread, I posted the Decware DNA BLH to see if there was any interest in doing a DIY version of it in easy foam core. See post here: Foam Core Board Speaker Enclosures? - Page 175 - diyAudio
Here is Bcmbob's build in XPS foam:
There is some interest in proceeding with it as I can see that as of now, there have been 32 views of the approximate dimensions that I posted as a pdf plan here: diyAudio
The DNA was designed for use with the now discontinued TB W5-1880 driver. In the interest of trying this design out in FC on a budget, I spec'd the following cheap 5 in aluminum cone driver from MCM: MCM Audio Select 5'' Aluminum Cone Woofer | 55-1870 (551870) | MCM Audio Select
I simulated the DNA in AkAbak with the following horn expansion profile that I derived using dial calipers from the drawing (13 segments total with the first one being the throat leading to the main horn passage. The throat width is equivalent for a 2.5 in dia hole.)
The main driver chamber was estimated to have a volume of 16.1 liters, and the throat hole leading from the chamber to the start of the horn passage is assumed to be 2.5 in dia.
The result of the simulation for the DNA with the W5-1880 driver appears to go down to about 30 Hz in bass extension - not bad. This is for the speaker placed with baffle 18 in from rear wall and 4 watts of power with listening position at 3 meters away from front baffle.
For the cheap $13 MCM drivers, I had to reduce the driver chamber volume by 6 liters to 10.1 L and this provided a much better response due to the much stiffer suspension (smaller Vas). With this driver, the bass shelf is a little tilted but nonetheless smooth and goes down to 40 Hz. The last plot shows the driver cone displacement for the MCM 55-1870 driver at 4 watts. With appropriate stuffing in the main driver chamber the resonances and peaks should be reduced significantly - so ignore the sharp peaks when viewing the plots. I still have not figured out how to implement damping/stuffing in AkAbak.
The design appears to a good one and I think worth pursuing even with the budget driver - 40 Hz extension and it appears that there may be enough bass gain to avoid using a BSC.
Some recent plans from DimeStore Dynaco:
Here is Bcmbob's build in XPS foam:
There is some interest in proceeding with it as I can see that as of now, there have been 32 views of the approximate dimensions that I posted as a pdf plan here: diyAudio
The DNA was designed for use with the now discontinued TB W5-1880 driver. In the interest of trying this design out in FC on a budget, I spec'd the following cheap 5 in aluminum cone driver from MCM: MCM Audio Select 5'' Aluminum Cone Woofer | 55-1870 (551870) | MCM Audio Select
I simulated the DNA in AkAbak with the following horn expansion profile that I derived using dial calipers from the drawing (13 segments total with the first one being the throat leading to the main horn passage. The throat width is equivalent for a 2.5 in dia hole.)
Code:
| Define Horn Segments (need to multiply by Width for area, dims in inches * 0.0254 in/m): S_Throat, S_Mouth, Length
S1T=0.70*0.0254; S1M=0.701*0.0254; L1=0.18*0.0254;
S2T=0.64*0.0254; S2M=0.76*0.0254; L2=5.09*0.0254;
S3T=0.76*0.0254; S3M=1.30*0.0254; L3=5.09*0.0254;
S4T=1.30*0.0254; S4M=2.01*0.0254; L4=16.08*0.0254;
S5T=2.01*0.0254; S5M=2.88*0.0254; L5=6.03*0.0254;
S6T=2.88*0.0254; S6M=2.89*0.0254; L6=1.47*0.0254;
S7T=2.88*0.0254; S7M=4.02*0.0254; L7=3.35*0.0254;
S8T=4.02*0.0254; S8M=4.29*0.0254; L8=1.30*0.0254;
S9T=4.29*0.0254; S9M=4.30*0.0254; L9=2.68*0.0254;
S10T=3.83*0.0254; S10M=4.52*0.0254; L10=1.45*0.0254;
S11T=4.52*0.0254; S11M=6.16*0.0254; L11=7.64*0.0254;
S12T=6.16*0.0254; S12M=7.41*0.0254; L12=3.40*0.0254;
S13T=7.41*0.0254; S13M=15.68*0.0254; L13=5.23*0.0254;The main driver chamber was estimated to have a volume of 16.1 liters, and the throat hole leading from the chamber to the start of the horn passage is assumed to be 2.5 in dia.
The result of the simulation for the DNA with the W5-1880 driver appears to go down to about 30 Hz in bass extension - not bad. This is for the speaker placed with baffle 18 in from rear wall and 4 watts of power with listening position at 3 meters away from front baffle.
For the cheap $13 MCM drivers, I had to reduce the driver chamber volume by 6 liters to 10.1 L and this provided a much better response due to the much stiffer suspension (smaller Vas). With this driver, the bass shelf is a little tilted but nonetheless smooth and goes down to 40 Hz. The last plot shows the driver cone displacement for the MCM 55-1870 driver at 4 watts. With appropriate stuffing in the main driver chamber the resonances and peaks should be reduced significantly - so ignore the sharp peaks when viewing the plots. I still have not figured out how to implement damping/stuffing in AkAbak.
The design appears to a good one and I think worth pursuing even with the budget driver - 40 Hz extension and it appears that there may be enough bass gain to avoid using a BSC.
Some recent plans from DimeStore Dynaco:
Attachments
SigmaStudios- DSPB-K DSP Kernel Board and DSPB-KE Kernel DSP Expansion 2-In 3-Out
- By Bergarth
- Digital Line Level
- 2 Replies
