Creek Audio T50: LCD issue displays gibberish when brightness level is Off
- By gghodg
- Analogue Source
- 3 Replies
Attachments
Pioneer PD-106 : CD which does not turn systematically
- By Zozor
- Digital Source
- 5 Replies
Hi there,
I need your suggestions please. It's a curious failure, at least for me.
Most of the time, we insert a disc (in perfect condition) and it fits correctly in its slot.
The disk does not turn, we hear the actuator click while it makes several movements, then nothing and the display indicates zeros.
We eject the trapdoor and its disk several times AND! the disc starts to spin, the Toc is read immediately.
We insist on the "read" button, the actuator clicks once, the disc does not turn.
We take the disc out several times, but this time we press the “play” button directly.
At some point, reading will start !
The entire disc can be played perfectly, without skipping. You can skip back and forth between tracks, change tracks at will !
As soon as you stop the disk, it will not restart. We eject the disc several times and wait for the next reading ! 👽
Notes :
- The soldering under the card was bad originally. it is poor in tin and under the soldering iron, the component legs refuse to solder.
We see in this photo the difficulty :
- I also looked under the optical unit. Maybe a problem with the cms capacitors?
I didn't see anything special on the weld side.
- I then saw that the rubber suspensions of the chassis were all dead !
- I temporarily replaced these suspensions with plumbing washers on hand I had. No improvement.
In any case, even if the chassis is poorly suspended or crooked, the spindle remains aligned on its common chassis facing the optics.
isn't it ?
(and the CD did not rub when turning)
I find it hard to question the optics since when the reader works, it works perfectly.
It's a PEA1335, unobtainable or overpriced !
What can I do now ? Can you help me please ?
Doc here : https://elektrotanya.com/pioneer_pd-106_sm.pdf/download.html
I need your suggestions please. It's a curious failure, at least for me.
Most of the time, we insert a disc (in perfect condition) and it fits correctly in its slot.
The disk does not turn, we hear the actuator click while it makes several movements, then nothing and the display indicates zeros.
We eject the trapdoor and its disk several times AND! the disc starts to spin, the Toc is read immediately.
We insist on the "read" button, the actuator clicks once, the disc does not turn.
We take the disc out several times, but this time we press the “play” button directly.
At some point, reading will start !
The entire disc can be played perfectly, without skipping. You can skip back and forth between tracks, change tracks at will !
As soon as you stop the disk, it will not restart. We eject the disc several times and wait for the next reading ! 👽
Notes :
- The central motor has been checked with an external power supply and is working well. I added a drop of oil to the axle.
- I looked at the cable connections to the motherboard, but no false contact
- Using the multimeter on the central motor connector of the motherboard, I have between 4 and 2 volts when the disk is spinning. No voltage when the disk is not spinning.
- Belts have been checked, no problem.
- I also noticed that the LA6520 (ic202) is hot when the second one is cold (there are two on this card)
- The control panel is not the cause, we see the actuator move with each selection.
- There is nothing visually suspicious about the electronic components.
- The soldering under the card was bad originally. it is poor in tin and under the soldering iron, the component legs refuse to solder.
We see in this photo the difficulty :
A view of the entire board :
- I also looked under the optical unit. Maybe a problem with the cms capacitors?
I didn't see anything special on the weld side.
- I then saw that the rubber suspensions of the chassis were all dead !
- I temporarily replaced these suspensions with plumbing washers on hand I had. No improvement.
In any case, even if the chassis is poorly suspended or crooked, the spindle remains aligned on its common chassis facing the optics.
isn't it ?
(and the CD did not rub when turning)
I find it hard to question the optics since when the reader works, it works perfectly.
It's a PEA1335, unobtainable or overpriced !
What can I do now ? Can you help me please ?
Doc here : https://elektrotanya.com/pioneer_pd-106_sm.pdf/download.html
Desktop full range
- By lezzmeister
- Full Range
- 8 Replies
So I had these on my desktop, and they are deceased after 2 decades of loyal service. Also a tad large, but I liked them a whole lot.
So after a lot of searching and reading (sitting close and phase, open baffle and wall, imaging, that tweeter has ehm questionable reviews apparently), I think the best and easiest option is a nice fullrange in closed box, either a Fane or a Sica, this is (probably?) as large as I can get away with next to my screen. But I'd like to avoid an absolutely huge box.
What is the smallest housing for either of these that I can get away with, is 45-47 liter good? Is it stupid to even ask and am I then better off with 10 inch drivers? About 50% music, 50% games if relevant. I just want to get rid of these crappy Logitechs. Recommend other drivers if a lot better for a small box but try and cap it at say 2×-3× the price.
So after a lot of searching and reading (sitting close and phase, open baffle and wall, imaging, that tweeter has ehm questionable reviews apparently), I think the best and easiest option is a nice fullrange in closed box, either a Fane or a Sica, this is (probably?) as large as I can get away with next to my screen. But I'd like to avoid an absolutely huge box.
What is the smallest housing for either of these that I can get away with, is 45-47 liter good? Is it stupid to even ask and am I then better off with 10 inch drivers? About 50% music, 50% games if relevant. I just want to get rid of these crappy Logitechs. Recommend other drivers if a lot better for a small box but try and cap it at say 2×-3× the price.
Ian Canada HDMIPro => Topping D90 / Ian Canada TransportPiAES and Gentoo Player
- Digital Line Level
- 12 Replies
I'm new(ish) to using digital streaming. I had been successfully using Ropieee through a Raspberry Pi over the last 3 years or so. I used various DAC hats or USB outputs to various DACs.
I've now expanded my horizons, and I'm trying out some new things that I desperately do not wish to screw up.
After assembling some of the Ian Canada parts into a very basic setup, I have the Gentoo Player on the Raspberry Pi configured for USB output to a DAC. I set it up as a Roon Bridge, and it seems to be working quite well.
Now, I want to try out the other "fancy" Ian Canada parts to output the signal to the DAC properly over the various interface options.
A few (okay a lot of) questions:
First the I2S
In the manual for the Topping, it shows the following for phase:
It would seem that I would need to reverse the phase with the D90 (or just remember to do it in Roon, I think) - no big deal.
What's odd (to me) is that it shows the following for DSD:
If I'm interpreting this correctly (highly suspect) the two (Ian's board and the D90 with DSD) cannot match. I can either have the phase reversed or the channels reversed, correct? I don't play a lot of DSD, but I'd like to have it set up properly.
It seems like it may be easiest to change the DSD to DSDR Data to get the channels correct. I can leave the phase alone. It would be inverted for both types. Then, I can just leave the phase inverted in Roon, if I actually care at all about absolute phase... which... I don't really, but...
OR
Are those settings independent of each other? i.e. if I swap the phase in the preceding step, it ALSO applies to the DSD?
I can test all of this, but it would be nice to not need to fool with testing phase.
So, if anyone knows, I'd be grateful.
-------------------------------------------
Next the AES
Onto the one that I really don't have a clue about... Gentoo Player with the TransportPiAES.
Do I still leave the "DAC" in Gentoo Player as generic I2S when I swap over to that?
Also, does anyone know how to use the Ian Canada I2S and the AES boards in a stacked configuration? I'd love to have both options permanently mounted, so I don't have to swap back and forth. However, the Masterclock from the Fifopi can only go to one thing, I think. Any advice is appreciated.
Just getting the Gentoo Player set up and running was a monumental task. In hindsight, it's easy as Pi
It just had a steep learning curve for me. It's playing now, and it hasn't glitched, so... I'm leaving it alone... until I may need to change it for the AES board...
Edited to insert thumbnails vs. have the massive pics.
I've now expanded my horizons, and I'm trying out some new things that I desperately do not wish to screw up.
After assembling some of the Ian Canada parts into a very basic setup, I have the Gentoo Player on the Raspberry Pi configured for USB output to a DAC. I set it up as a Roon Bridge, and it seems to be working quite well.
Now, I want to try out the other "fancy" Ian Canada parts to output the signal to the DAC properly over the various interface options.
A few (okay a lot of) questions:
First the I2S
- I assume in Gentoo player one would select the "DAC" as Generic I2S, correct?
- Then, as but one example, I have a few DACs. One is a Topping D90. I noticed that the pinout for the Ian Canada board is:
In the manual for the Topping, it shows the following for phase:
It would seem that I would need to reverse the phase with the D90 (or just remember to do it in Roon, I think) - no big deal.
What's odd (to me) is that it shows the following for DSD:
If I'm interpreting this correctly (highly suspect) the two (Ian's board and the D90 with DSD) cannot match. I can either have the phase reversed or the channels reversed, correct? I don't play a lot of DSD, but I'd like to have it set up properly.
It seems like it may be easiest to change the DSD to DSDR Data to get the channels correct. I can leave the phase alone. It would be inverted for both types. Then, I can just leave the phase inverted in Roon, if I actually care at all about absolute phase... which... I don't really, but...
OR
Are those settings independent of each other? i.e. if I swap the phase in the preceding step, it ALSO applies to the DSD?
I can test all of this, but it would be nice to not need to fool with testing phase.
So, if anyone knows, I'd be grateful.
-------------------------------------------
Next the AES
Onto the one that I really don't have a clue about... Gentoo Player with the TransportPiAES.
Do I still leave the "DAC" in Gentoo Player as generic I2S when I swap over to that?
Also, does anyone know how to use the Ian Canada I2S and the AES boards in a stacked configuration? I'd love to have both options permanently mounted, so I don't have to swap back and forth. However, the Masterclock from the Fifopi can only go to one thing, I think. Any advice is appreciated.
Just getting the Gentoo Player set up and running was a monumental task. In hindsight, it's easy as Pi
It just had a steep learning curve for me. It's playing now, and it hasn't glitched, so... I'm leaving it alone... until I may need to change it for the AES board...Edited to insert thumbnails vs. have the massive pics.
Acoustat Interface MK-121-2 - Minimizing the Bias Transformer Hum Noise
- By John Tulett
- Planars & Exotics
- 0 Replies
Preface
* Initially I experimented with grommets to modify the bias transformer mounting, but the most effective result came from using rubber anti-vibration studs to isolate the vibrations (Fig. 1).
Figure 1. Elesa VD1-1510M4 (left) not used, and Elesa VD1-1515M4 (right) used in this installation.
Table 1. Specifications of Elesa Type VD1 Rubber Vibration Dampers - dimensions in mm.
* A full set of specifications for the VD1 series can be obtained from the attached specification sheet. An optional stainless-steel version VD1-SUS is available for wet or corrosive applications but isn't needed here.
Preparation
Figure 2. Pre-assembly showing wiring harness for connecting both ends of each VD1-1515M4.
Figure 3. Partial assembly, VD1-1515M4 pair and wiring harness attached to transformer base.
Figure 4. Bias transformer reinstalled with new VD1-1515M4 pair and ground wiring.
* Fortunately, this installation using the VD1-1515M4 pair allowed just enough clearance between the bias transformer housing and the large 50 K ohm resistor (Fig. 4).
Results
- This report is a follow-up to, "Acoustat Magne-Kinetic Interface MK-121-2 - A Successful Restoration" https://www.diyaudio.com/community/...ace-mk-121-2-a-successful-restoration.404764/
- As stated in this restoration report, "Initial Symptoms. When powered up, annoying hum noise coming from both interfaces." This noise issue was addressed in section "Minimization of 50 Hz induced hum noise" accompanied by Figures 19 and 20 in the report, whereby applying synthetic rubber sheeting to the chassis was effective in reducing the hum noise.
- However, I was intrigued by the comment from Mr. AAM from his review of my report where he kindly replied with, "And speaking of the bias transformer, later units had the transformer mounted on rubber grommets, alleviating the "chassis hum" you experienced."
- As these are my only pair of Acoustat electrostatic loudspeakers having purchased them new in 1980, I would never have known about this subsequent change to the transformer mounting. So, thanks to Mr. AAM for sharing this information, it got me thinking!
- While the initial restoration report addressed reducing the hum noise, the purpose of this report is to minimize the noise vibrations at its source.
- Without having information about how the transformer mounting was changed in subsequent production or the parts involved, another purpose of this report is to share with our members an inexpensive solution using commercially available parts.
* Initially I experimented with grommets to modify the bias transformer mounting, but the most effective result came from using rubber anti-vibration studs to isolate the vibrations (Fig. 1).
Figure 1. Elesa VD1-1510M4 (left) not used, and Elesa VD1-1515M4 (right) used in this installation.
- Two vibration dampers are required for each bias transformer, or total 4 for the pair of speakers.
- Of the two series of vibration dampers purchased, VD1-1510M4 of rubber height 10mm and VD1-1515M4 of rubber height 15mm, I decided to first try the VD1-1515M4 as it had the softer spring constant (Table 1). In the event of insufficient clearance between the bias transformer housing and the high-voltage board with the VD1-1515M4, then I would change to the lower profile VD1-1510M4.
- An M4 thread type was chosen as the M4 diameter was close to the diameter of the original mounting hardware, whereas the next size up M6 would require enlarging the chassis holes.
Table 1. Specifications of Elesa Type VD1 Rubber Vibration Dampers - dimensions in mm.
* A full set of specifications for the VD1 series can be obtained from the attached specification sheet. An optional stainless-steel version VD1-SUS is available for wet or corrosive applications but isn't needed here.
Preparation
- Safety. Ensure the AC power cord is disconnected, and the high voltage circuit has been fully discharged.
- A consequence of the rubber damping material is it isolates the earth connection between transformer housing and chassis. Proper grounding is very important, both for safety and to complete the connection to the bias high voltage.
- To re-establish the ground connection a small wiring harness was constructed (Fig. 2).
Figure 2. Pre-assembly showing wiring harness for connecting both ends of each VD1-1515M4.
Figure 3. Partial assembly, VD1-1515M4 pair and wiring harness attached to transformer base.
- The inside surface of the interface's chassis was lightly sanded around the mounting holes to ensure a bare metal contact with the grounding wire lugs.
- Finally, the bias transformer with wiring harness and anti-vibration studs was installed back in the interface using M4 fastening hardware (Fig. 4).
Figure 4. Bias transformer reinstalled with new VD1-1515M4 pair and ground wiring.
* Fortunately, this installation using the VD1-1515M4 pair allowed just enough clearance between the bias transformer housing and the large 50 K ohm resistor (Fig. 4).
Results
- After installing these parts and upon powering up I was pleasantly relieved all transformer hum noise is gone, both interfaces are now dead quiet. Considering the parts cost less than $5 per interface this was a worthwhile modification.
- Previously when placing your hand on the interface chassis you could feel the vibrations, but this is greatly diminished now.
- Regarding the initial approach of attaching synthetic rubber isolation sheets to the chassis, this was left in place as it does no harm.
- Side note, while the reduction in hum noise was clearly apparent, I was not expecting any changes in the audio sound quality. But there is a very subtle improvement with a clearer, more open sound. I don't think I'm imagining things as I have owned these speakers for 44 years and am accustomed to their amazing sound quality, on the other hand I cannot quantify in measurements what I have heard. While it's difficult to say, one theory might be the previous mechanical vibrations throughout the chassis impacted the performance of different components, whereas these chassis vibrations are now considerably diminished.
- Why it took me so long to act on Mr. AAM's comment regarding transformer isolation? To be honest the biggest priority after restoring the interfaces was repairing the multiple broken stator wire joints, documented in "Acoustat Stator Wire Repair: Hints and Lessons Learned" and this effort took over a year to complete before I could address the transformer hum. https://www.diyaudio.com/community/...wire-repair-hints-and-lessons-learned.404881/
- As mentioned, I purchased two series of vibration dampers, VD1-1510M4 of rubber height 10mm which I kept as spare, and VD1-1515M4 of rubber height 15mm which I installed and documented in this report. Should one day the VD1-1515M4 rubber become soft and the bias transformer begins to sag, my plan is to change to the lower profile VD1-1510M4 having a higher spring constant (Table 1).
- While not documented in this report, other makes of similar anti-vibration hardware could give similar results.
- VD1 series, Japanese. https://www.imao.co.jp/files/ja/pdf/vd1.pdf
- VD1 series, English. https://www.imao.com/files/en/pdf/vd1-e.pdf
For Sale My_ref Fremen 1.02 gainclone power amplifier dual mono. Working well
- By gilbodavid
- Swap Meet
- 1 Replies
Working very well. Good quality parts.
£100 Ono
£100 Ono
DIY KEF Blade Coax + Dayton RS180 midbass array in baffle wall
I have 3x KEF Blade Coax drive units that I want to use in a new setup in a new house, together with 8x Dayton RS180 per side in a baffle wall.
(I have 3 of these nice coaxes, so there will also be a center speaker with the same setup but with only 4 RS180 mid)
Does anyone here know how to calculate spacing and possibly distance from floor and ceiling, and possibly have general thoughts about solutions?
Appreciate feedback and discussions!
My thoughts are in this way to solve a lot of the room nodes in the elevation plan. Split frequency will be considered, but around 4-500hz possibly with some overlap.
Originally Kef Blade is shared at 320hz, but I personally feel it is a bit low. There will be a subwoofer to take the bass area.
I have a Minidsp OpenDRC-DA8 for active crossover incl FIR.
See picture for alternative placements of mids.
In one set-up, the coax is at a height of approx. 1.25m, which I feel is somewhat high compared to the approx. 1m sitting position?
(I have 3 of these nice coaxes, so there will also be a center speaker with the same setup but with only 4 RS180 mid)
Does anyone here know how to calculate spacing and possibly distance from floor and ceiling, and possibly have general thoughts about solutions?
Appreciate feedback and discussions!
My thoughts are in this way to solve a lot of the room nodes in the elevation plan. Split frequency will be considered, but around 4-500hz possibly with some overlap.
Originally Kef Blade is shared at 320hz, but I personally feel it is a bit low. There will be a subwoofer to take the bass area.
I have a Minidsp OpenDRC-DA8 for active crossover incl FIR.
See picture for alternative placements of mids.
In one set-up, the coax is at a height of approx. 1.25m, which I feel is somewhat high compared to the approx. 1m sitting position?
Attachments
How would you drive an EL509 in enhanced triode mode.
- By Bas Horneman
- Tubes / Valves
- 200 Replies
Attachments
REL Studio II relay clicking
- By mjz3348
- Subwoofers
- 6 Replies
I powered down and unplugged my working REL Studio II for a planned power outage to repair a utility pole. Two hours later, when I turned the sub back on, the drivers relay began to click on/off. No sound could be heard except for a brief moment when the relay tried to connect the speaker drivers to the audio circuits. Needless to say, my sub is no longer working.
Visual inspection of the board show the caps to be in like new condition (no bulging or leaks anywhere). In fact the whole board looks brand new.
This sub was always left on and only turned off either due to infrequent power outages (storms) or when away for an extended time. Otherwise, the powered sub is always on.
Has anyone experienced this where only the relay is faulty or is it the power supply causing the clicking? I haven't tested any voltages yet needing advice on what/where to test. See image below for the relay picture. I can't find a schematic for this unit.
I did measure the relay's coil voltage and it fluctuates with each click - rising to a few volts then falling to zero. My digital meter is not fast enough to catch it because the click is so fast.
Thanks
Visual inspection of the board show the caps to be in like new condition (no bulging or leaks anywhere). In fact the whole board looks brand new.
This sub was always left on and only turned off either due to infrequent power outages (storms) or when away for an extended time. Otherwise, the powered sub is always on.
Has anyone experienced this where only the relay is faulty or is it the power supply causing the clicking? I haven't tested any voltages yet needing advice on what/where to test. See image below for the relay picture. I can't find a schematic for this unit.
I did measure the relay's coil voltage and it fluctuates with each click - rising to a few volts then falling to zero. My digital meter is not fast enough to catch it because the click is so fast.
Thanks
WinISD: Sealed box construction for midrange (Questions)
- By Pedroga
- Software Tools
- 13 Replies
Attachments
Help identifying resistor on KEF SP1052 dividing network (KEF Corelli)
So, opened up a mint condition KEF Corelli speaker set. Manufacturing seems to be Mar-May of 1978 based on the stamps on the driver (1974), Dividing network and enclosure.
Everything looks in great shape, just looking to replace the Caps and spotted the resistor starting to fur out. W22, 3RO.
I believe the 3RO means 3 Ohm resistor. Is the W22 the wattage? Google tells me it's a type of wire-wound resistor.
What would be a safe wattage/power rating to not blow/damage the T27/B200 drivers.
Thanks in advance!
For anyone looking for the SP1052 dividing network photos:
Everything looks in great shape, just looking to replace the Caps and spotted the resistor starting to fur out. W22, 3RO.
I believe the 3RO means 3 Ohm resistor. Is the W22 the wattage? Google tells me it's a type of wire-wound resistor.
What would be a safe wattage/power rating to not blow/damage the T27/B200 drivers.
Thanks in advance!
For anyone looking for the SP1052 dividing network photos:
For Sale Circuitbasics.com LM3886 power amplifier
- By gilbodavid
- Swap Meet
- 2 Replies
Fully built amplifier working.
One channel is about 6db down. This may be a wrong value resistor. I don't have the knowledge to sort it. Hopefully someone else can, and enjoy this amplifier.
£100 plus postage obo.
I'm in Guildford Surrey.
thanks, David
One channel is about 6db down. This may be a wrong value resistor. I don't have the knowledge to sort it. Hopefully someone else can, and enjoy this amplifier.
£100 plus postage obo.
I'm in Guildford Surrey.
thanks, David
For Sale 2SK1530 + 2SJ201 - 4 pairs (originals from tme.eu)
- By thefirstdj
- Swap Meet
- 3 Replies
I am selling 4 pairs of 2SK1530 and 2SJ201 Toshiba originals bought many years ago from tme.eu.
They were for a project with lme49830 that I wanted to make but never had the time.
If interested, I also have lme49830.
Price is 80 euro for all 4 pairs plus shipping.
I ship only in EU, the shipping cost is between 15 and 30 euro depending on the country.
Thanks!
They were for a project with lme49830 that I wanted to make but never had the time.
If interested, I also have lme49830.
Price is 80 euro for all 4 pairs plus shipping.
I ship only in EU, the shipping cost is between 15 and 30 euro depending on the country.
Thanks!
3-way to 3.5-way conversion
I have a plan to convert my speakers from originally 3-way to 3.5-way system. Each speaker consists of a 0.75" tweeter, a 2" dome midrange, and two 10" woofers.
I use VituixCAD2 for the simulation tool. Let's see the original crossover circuit and its response. Specification of each driver is indicated in the schematic.
The target of this conversion is to split operating range between two woofers. One woofer, the upper unit, will be responsible for lower midrange and bass, while the other, the lower unit, will cover only for bass of lower than 100Hz region. It's just like the integrated subwoofer concept.
New schematic is shown below.
The plan/concept is to disconnecting lower woofer first, then the SPL on woofers' region will drop, some attenuations on midrange and tweeter may be required. After that, reconnect the lower woofer and build a new crossover for it (L2) along with tweaking original crossover (L1, C1) for the upper woofer.
The problem is I had tried random values for L1, C1, and L2 many times in the simulator, I couldn't achieve the target though. I need advice which directions should be applied to those parameters to achieve the target. Or is my objective achievable by this plan?
I use VituixCAD2 for the simulation tool. Let's see the original crossover circuit and its response. Specification of each driver is indicated in the schematic.
The target of this conversion is to split operating range between two woofers. One woofer, the upper unit, will be responsible for lower midrange and bass, while the other, the lower unit, will cover only for bass of lower than 100Hz region. It's just like the integrated subwoofer concept.
New schematic is shown below.
The plan/concept is to disconnecting lower woofer first, then the SPL on woofers' region will drop, some attenuations on midrange and tweeter may be required. After that, reconnect the lower woofer and build a new crossover for it (L2) along with tweaking original crossover (L1, C1) for the upper woofer.
The problem is I had tried random values for L1, C1, and L2 many times in the simulator, I couldn't achieve the target though. I need advice which directions should be applied to those parameters to achieve the target. Or is my objective achievable by this plan?
Audionics of Oregon BT-2 Preamplifier Overhaul
- By bazzle592
- Analog Line Level
- 22 Replies
Hello all-
I recently picked up this Audionics of Oregon stack for cheap - a BT-2 preamplifier with a PZ3 Series II amplifier.
They were sold as-is, and upon testing, I found the preamp to sound very good, but it exhibits the classic snap-crackle-pop-fizz of failing silicon.
The folks at Audionics decided to pot the circuit boards, presumably to protect their IP. Unfortunately, this made them absolutely impossible to service. They were violating right to repair way before it was cool!
I tried replacing the two small signal transistors that weren't potted, but they didn't have any effect. Based off of the 8-pin packages visible from the bottom, this looks like a simple op-amp based line amplifier to me. Even if I could service the board, finding these ancient op-amps would be a tall order in itself.
I love the simplicity and weight of the chassis, and the switches/pots are of very high quality, so I would like to revive this preamp by installing modern boards.
What are some favorite DIY preamp boards of the forum? I think I would like to keep it op-amp based to keep in the spirit of the original circuitry, but am open to discrete ideas as well. I want to buy boards in kit or pre-assembled form, not looking to break out the proto board this time. I don't mind buying PCBs and parts separately though.
I would like to replace both the line and phono boards, so suggestions for both are welcome.
Thanks!
I recently picked up this Audionics of Oregon stack for cheap - a BT-2 preamplifier with a PZ3 Series II amplifier.
They were sold as-is, and upon testing, I found the preamp to sound very good, but it exhibits the classic snap-crackle-pop-fizz of failing silicon.
The folks at Audionics decided to pot the circuit boards, presumably to protect their IP. Unfortunately, this made them absolutely impossible to service. They were violating right to repair way before it was cool!
I tried replacing the two small signal transistors that weren't potted, but they didn't have any effect. Based off of the 8-pin packages visible from the bottom, this looks like a simple op-amp based line amplifier to me. Even if I could service the board, finding these ancient op-amps would be a tall order in itself.
I love the simplicity and weight of the chassis, and the switches/pots are of very high quality, so I would like to revive this preamp by installing modern boards.
What are some favorite DIY preamp boards of the forum? I think I would like to keep it op-amp based to keep in the spirit of the original circuitry, but am open to discrete ideas as well. I want to buy boards in kit or pre-assembled form, not looking to break out the proto board this time. I don't mind buying PCBs and parts separately though.
I would like to replace both the line and phono boards, so suggestions for both are welcome.
Thanks!
problems with REW measurements - suspected amplifier malfunction
- By arivel
- Equipment & Tools
- 3 Replies
Attachments
Mitchell & Johnson power amp schematic?
- By Sarchi
- Solid State
- 10 Replies
I have an M&J S815 power amp, working fine, but since they're out of business with no contact info, can anyone help me locate a schematic? I've talked to the local importer and they had no info.
Is this a gimmick?
- Multi-Way
- 45 Replies
Scanspeak came out with these. It’s hard to believe that an oval voice coil would have less distortion than a round one does. I guess that’s why they aren’t showing distortion specs. Distortion probably sells fewer speakers than style does. I have no doubt they have low distortion, but how much does the voice coil shape matter?
A little tube porn: "Gossamer" VT-62 (RAF) SE A2 amp
- By pmillett
- Tubes / Valves
- 11 Replies
Finally built some amps using the VT-62 (RAF) triode (basically 4304CB or DET12, or 834 with a B4 base). Conservatively about 15 watts out. Hot as heck.
Driver is a triode/pentode with the pentode a DC coupled cathode follower to drive the VT-62.
Details at http://www.pmillett.com/gossamer.html
Driver is a triode/pentode with the pentode a DC coupled cathode follower to drive the VT-62.
Details at http://www.pmillett.com/gossamer.html
Tokin THF-51S Pairs NOS
SOLD !
New unused Tokin THF-51s "Precisely" matched pairs (2pcs) with curve traces that I purchased from Tomoaki Watanabe recently. Still have 1 pair available. Watanabe is now fet-tokyo on ebay
$200./pair with Free shipping (US 48 only)
New unused Tokin THF-51s "Precisely" matched pairs (2pcs) with curve traces that I purchased from Tomoaki Watanabe recently. Still have 1 pair available. Watanabe is now fet-tokyo on ebay
$200./pair with Free shipping (US 48 only)
Bourbon Barrel Speakers
- Full Range
- 21 Replies
Whenever my friend Brandon Boyd comes over, we listen to music and drink bourbon.
He is a vendor who did some excellent work for my company. So I built him a pair of speakers.
In building these, I wanted to “channel” Brandon. He loves bourbon. And since he’s got enough personality for five people....
....the obvious solution was to make him a 10” subwoofer out of a bourbon cask (18 liters volume, purchased on Etsy) with full range satellites using front and back panels made from 4” wide bourbon staves; also purchased from Etsy.
He was absolutely THRILLED - this is a photo of him seeing them for the first time:
Staves from standard bourbon barrels are ~4” wide and 34” long. Perfect for a slim set of satellites built around a 3.5” Tang Band full range driver. Carpenter Seth Cothron fashioned these into a set of full range back-loaded horns. They cross over at 130Hz to the 10” subwoofer using a MiniDSP 2x4HD.
The driver for the satellites is a Tang Band W3-871SC wideband unit. The back of the satellites features a tweeter, a Dayton ND20FA-6 3/4" Soft Dome Neodymium for rear fill. Tweeter crossover a 4 uF capacitor. I added a 100uF capacitor to protect the Tang Band 3.5" full range from mishaps.
The subwoofer is a GRS 10PT-8 10" in a reflex box tuned to 45Hz with a 3” Precision Port flared port tube. Woofer on one end, port on the other. A 4 channel x 35 watt Yamaha amplifier does a splendid job. If you drive the satellites with tubes, they sound even better.
Active crossover frequency is 130Hz. The back loaded horn (designed using the old Transmission Line program by Leonard Audio) has the driver placed at the optimum point to cancel the 3xFb resonance.
This is the drawing carpenter Seth Cothron used to make the satellites:
The front and back panels are made from staves, which are naturally curved. They are also extremely rigid and inert.
The semicircle on each side at the bottom functions as the port for the horn. These horns are deliberately designed to produce a 7-10dB peak at 150Hz, so combined with an active crossover that kicks in at about 200Hz, the 3.5” driver with its very limited displacement gains maximum leverage with little strain. It can produce significant output with little power and very little excursion.
I love using back loaded horns with small full range drivers. These speakers have a huge sound and soundstage that belies their tiny size. They simply sound far bigger than they are. I have built many larger and more sophisticated systems, like the award winning Live Edge Dipoles. But I took these to the Dayton 2023 Speaker Design Competition and got very positive comments from the judges.
This is a frequency response of both near field output of the horn and near field output of the Tang Band 3.5: driver, overlaid on top of each other:
I am extremely happy with this. What these curves say is: below 1500Hz the horn exit produces most of the output and above 1500, the driver takes over. It's not possible to exactly match the levels of these curves. The system sounds fantastic with almost no EQ beyond the basic crossover and 45Hz bass boost for the small reflex sub.
The rear firing 3/4” tweeter compensates for the narrowing dispersion of the full range driver and adds a LOT more space and air to the soundstage.
They sound fantastic about 3 feet out from the front wall.
In theory, a bourbon barrel is a fantastic speaker cabinet because the barrels are made of white oak, they are extremely rigid and again in theory they are sealed.
In real life, bourbon barrels are charred. (This impacts the flavor, color, and overall character of the bourbon, as it interacts with the wood during the aging process.) It also makes speaker building a little messy, and I found out a “retired” bourbon barrel has lots of leaks which need to be sealed before it properly functions as a speaker.
I mounted speaker terminals in the bung hole, and purchased 1.5” feet to suspend the cabinet above the floor. I also installed a handle on the top so it could be carried.
The MiniDSP EQ is pretty simple: The satellites sound great with nothing but a 24dB/octave filter at 200Hz... which, because of the rising response of the port around 150Hz, makes for an effective acoustic crossover at 130Hz. The subwoofer has a 12dB/octave slope at 120Hz and a +7dB peak at 45Hz (the port tuning frequency) with steep rolloff below. I have attached the family of DSP EQ XML files for this system in a ZIP file.
These can play plenty loud and have superb stereo imaging, huge soundstage, a full body and depth that you simply do not expect from a 3.5" driver.
Above: My demo at Parts Express 2023 Speaker Design Competition. They judges and audience had many positive comments. Someone even asked me, "Are you an artist?".
Happy Wife
The wife of another friend came over to my place while I was building these. She walked in the room and FLIPPED OUT. (How often do women FLIP OUT over speakers???) She said "You HAVE to build me a pair for John for Christmas" so I obliged.
Two of these Bourbon Barrel Speakers now exist in the world. I encourage you to mint your own version of these. Very fun, great sound with a huge Wife Appreciation Factor.
He is a vendor who did some excellent work for my company. So I built him a pair of speakers.
In building these, I wanted to “channel” Brandon. He loves bourbon. And since he’s got enough personality for five people....
....the obvious solution was to make him a 10” subwoofer out of a bourbon cask (18 liters volume, purchased on Etsy) with full range satellites using front and back panels made from 4” wide bourbon staves; also purchased from Etsy.
He was absolutely THRILLED - this is a photo of him seeing them for the first time:
Staves from standard bourbon barrels are ~4” wide and 34” long. Perfect for a slim set of satellites built around a 3.5” Tang Band full range driver. Carpenter Seth Cothron fashioned these into a set of full range back-loaded horns. They cross over at 130Hz to the 10” subwoofer using a MiniDSP 2x4HD.
The driver for the satellites is a Tang Band W3-871SC wideband unit. The back of the satellites features a tweeter, a Dayton ND20FA-6 3/4" Soft Dome Neodymium for rear fill. Tweeter crossover a 4 uF capacitor. I added a 100uF capacitor to protect the Tang Band 3.5" full range from mishaps.
The subwoofer is a GRS 10PT-8 10" in a reflex box tuned to 45Hz with a 3” Precision Port flared port tube. Woofer on one end, port on the other. A 4 channel x 35 watt Yamaha amplifier does a splendid job. If you drive the satellites with tubes, they sound even better.
Active crossover frequency is 130Hz. The back loaded horn (designed using the old Transmission Line program by Leonard Audio) has the driver placed at the optimum point to cancel the 3xFb resonance.
This is the drawing carpenter Seth Cothron used to make the satellites:
The front and back panels are made from staves, which are naturally curved. They are also extremely rigid and inert.
The semicircle on each side at the bottom functions as the port for the horn. These horns are deliberately designed to produce a 7-10dB peak at 150Hz, so combined with an active crossover that kicks in at about 200Hz, the 3.5” driver with its very limited displacement gains maximum leverage with little strain. It can produce significant output with little power and very little excursion.
I love using back loaded horns with small full range drivers. These speakers have a huge sound and soundstage that belies their tiny size. They simply sound far bigger than they are. I have built many larger and more sophisticated systems, like the award winning Live Edge Dipoles. But I took these to the Dayton 2023 Speaker Design Competition and got very positive comments from the judges.
This is a frequency response of both near field output of the horn and near field output of the Tang Band 3.5: driver, overlaid on top of each other:
I am extremely happy with this. What these curves say is: below 1500Hz the horn exit produces most of the output and above 1500, the driver takes over. It's not possible to exactly match the levels of these curves. The system sounds fantastic with almost no EQ beyond the basic crossover and 45Hz bass boost for the small reflex sub.
The rear firing 3/4” tweeter compensates for the narrowing dispersion of the full range driver and adds a LOT more space and air to the soundstage.
They sound fantastic about 3 feet out from the front wall.
In theory, a bourbon barrel is a fantastic speaker cabinet because the barrels are made of white oak, they are extremely rigid and again in theory they are sealed.
In real life, bourbon barrels are charred. (This impacts the flavor, color, and overall character of the bourbon, as it interacts with the wood during the aging process.) It also makes speaker building a little messy, and I found out a “retired” bourbon barrel has lots of leaks which need to be sealed before it properly functions as a speaker.
I mounted speaker terminals in the bung hole, and purchased 1.5” feet to suspend the cabinet above the floor. I also installed a handle on the top so it could be carried.
The MiniDSP EQ is pretty simple: The satellites sound great with nothing but a 24dB/octave filter at 200Hz... which, because of the rising response of the port around 150Hz, makes for an effective acoustic crossover at 130Hz. The subwoofer has a 12dB/octave slope at 120Hz and a +7dB peak at 45Hz (the port tuning frequency) with steep rolloff below. I have attached the family of DSP EQ XML files for this system in a ZIP file.
These can play plenty loud and have superb stereo imaging, huge soundstage, a full body and depth that you simply do not expect from a 3.5" driver.
Above: My demo at Parts Express 2023 Speaker Design Competition. They judges and audience had many positive comments. Someone even asked me, "Are you an artist?".
Happy Wife
The wife of another friend came over to my place while I was building these. She walked in the room and FLIPPED OUT. (How often do women FLIP OUT over speakers???) She said "You HAVE to build me a pair for John for Christmas" so I obliged.
Two of these Bourbon Barrel Speakers now exist in the world. I encourage you to mint your own version of these. Very fun, great sound with a huge Wife Appreciation Factor.
pair of identical speakers but one of the two works in reverse
Hi everyone .
I built a cardboard model because an image is essential to ask my question, otherwise it is difficult to explain using only words.
in the photograph you can see two identical speakers placed in a casing. for the moment let's establish that the box is closed and leave aside the type of loading.
we connect the two speakers to the same channel of the amplifier but to one of the two we apply the reversed polarity.
when one driver pushes forward the other pushes backwards and vice versa.
what happens inside the casing and on the cone of the two speakers?
I built a cardboard model because an image is essential to ask my question, otherwise it is difficult to explain using only words.
in the photograph you can see two identical speakers placed in a casing. for the moment let's establish that the box is closed and leave aside the type of loading.
we connect the two speakers to the same channel of the amplifier but to one of the two we apply the reversed polarity.
when one driver pushes forward the other pushes backwards and vice versa.
what happens inside the casing and on the cone of the two speakers?
![BARDIS3A52[1].png](/community/data/attachments/152/152612-30bd11b8c7fc1f33c7837b56c269d1c7.jpg?hash=ML0RuMf8Hz)
Jjasniew's Guitar Amp from Hammond model LA Husk
- By jjasniew
- Instruments and Amps
- 2 Replies
A place to document whatever it is I might do with this gift from a fellow player. I've got a grounded 3-wire cord in place to see if stable, bringing up/down on a Variac. I made the absolute sophomoric mistake of plugging my new set of Soviet "6V6 equivalent" tubes in it, plus another two 6V6 from the tube box, to see what would happen. Surprised I even had 8 6V6s on hand.
Ended up red-plating two of my new Soviets, instead of the two randos from the tube box - my idiocy / luck with the sox I happened to plug them into.
Replaced C10 / C11, which just one was leaky enough to put zero negative bias on the tube set that red plated. They were some kind of "Vitamin Q" look-alike, while C19 / C20 for the bass side are more std wax dipped jobs, that arent leaking. ~-15V on all 8 6L6 grids now, of course pairs tied. She idles fine now at full AC line.
This amp has the cool cathode windings in both OPTs, in the kinda-sorta McIntosh vein. Unsure what the coils L1, L2, L5 and L6 do, never seen anything like it. One of the pins of the protruding connector had 250V on it, so I snipped off that wire connecting through a large WW resistor to the B+. It's so nice to have found the schematic online, courtesy of captain-foldback.com which I've posted below. I'll mark it up as I go along.
T1 is an interesting bit under the hood - it's big. I've always wanted to do a guitar amp with transformer interstage coupling; maybe it'll work for that. But, what a gift; all I need to do is come across a spring set and connect it - there's my reverb channel with it's own amp / speaker. I have to wonder if this tranny once drove the big, tall Hammond necklace reverb, or one of the more ordinary 18" cans?
Ended up red-plating two of my new Soviets, instead of the two randos from the tube box - my idiocy / luck with the sox I happened to plug them into.
Replaced C10 / C11, which just one was leaky enough to put zero negative bias on the tube set that red plated. They were some kind of "Vitamin Q" look-alike, while C19 / C20 for the bass side are more std wax dipped jobs, that arent leaking. ~-15V on all 8 6L6 grids now, of course pairs tied. She idles fine now at full AC line.
This amp has the cool cathode windings in both OPTs, in the kinda-sorta McIntosh vein. Unsure what the coils L1, L2, L5 and L6 do, never seen anything like it. One of the pins of the protruding connector had 250V on it, so I snipped off that wire connecting through a large WW resistor to the B+. It's so nice to have found the schematic online, courtesy of captain-foldback.com which I've posted below. I'll mark it up as I go along.
T1 is an interesting bit under the hood - it's big. I've always wanted to do a guitar amp with transformer interstage coupling; maybe it'll work for that. But, what a gift; all I need to do is come across a spring set and connect it - there's my reverb channel with it's own amp / speaker. I have to wonder if this tranny once drove the big, tall Hammond necklace reverb, or one of the more ordinary 18" cans?
For Sale B1K Nutube
- Swap Meet
- 6 Replies
Up for sale is the Korg B1 nutube with SMPS PSU and upgraded Cornell Dubilier caps.
Asking EUR 125 plus shipping from the Netherlands.
Asking EUR 125 plus shipping from the Netherlands.
Aura CA200 dim LCD display
- By Chrisr3521
- Solid State
- 6 Replies
Just got round to fixing the output on this but have noticed that the LCD display is very dim. I've checked the +5v and -32v supply and they are fine, what should I check next?
Push-pull 520B DHT amp
- By pmillett
- Tubes / Valves
- 2 Replies
Since I was asked about it in another thread... I finally posted some info on my 520B amps. This uses Emission Labs 520B DHTs in push-pull for 45-50 watts out. Details are here: http://www.pmillett.com/520b.html
GAS PSP3500.1d going into protect
- By LatvianVideo
- Car Audio
- 74 Replies
Hello, repairing my brothers PSP3500.1D (or trying to). Issue in the title.
Tools I have: Multimeter (has diode mode, beep, etc), soldering iron
How it happened: He was listening to music at a low volume, shut off the car and went to the shops, when he came back the amp was dead.
What I've done: Opened it up, found a IRFB7437 with the drain leg melted (see image below). Its 4.7ohm (4R7) gate resistor also was dead. Replaced both, still goes into protect.
Diagnostics:
There is no short between the RCAs and speaker outputs
There is an increasing resistance (goes from ~0 to ~135ohm) between the power and ground terminal.
There is an increasing resistance (goes from ~0 to ~135ohm) between the drain and source (2nd and 3rd pin left to right) of all these fets (see image)
Rest of the fets seem fine
Other side of the amplfier:
I hope we will be able to find the issue, thank you in advance.
Tools I have: Multimeter (has diode mode, beep, etc), soldering iron
How it happened: He was listening to music at a low volume, shut off the car and went to the shops, when he came back the amp was dead.
What I've done: Opened it up, found a IRFB7437 with the drain leg melted (see image below). Its 4.7ohm (4R7) gate resistor also was dead. Replaced both, still goes into protect.
Diagnostics:
There is no short between the RCAs and speaker outputs
There is an increasing resistance (goes from ~0 to ~135ohm) between the power and ground terminal.
There is an increasing resistance (goes from ~0 to ~135ohm) between the drain and source (2nd and 3rd pin left to right) of all these fets (see image)
Rest of the fets seem fine
Other side of the amplfier:
I hope we will be able to find the issue, thank you in advance.
