btd Posted May 2, 2021 Posted May 2, 2021 Can be luck of the draw sometimes. Bought a cheap tong tester from Jaycar. On my third replacement from them and it still tells me I am drawing 1 to 3 amps DC when its just sitting on the bench. Gave up in the end as it measures AC well which is what I wanted. On the other hand I have a standard MM from them, similar price and same brand that has lasted years. Tony
crtexcnndrm99 Posted May 2, 2021 Posted May 2, 2021 Stumbled upon this design. Would be an interesting one to replicate for sure: from a reviewer’s description of the design - “Each speaker contains six 10” woofers, arranged one atop the other... The woofers are slot loaded such that three woofers are visible from the front, and the other three from the rear... Though all the woofers are oriented with their cones facing downward, they are wired with alternating phase so as to eliminate vibration.“ ”On top of the bass cabinet sits the “head unit,” which contains an 8” wide-band driver from Tangband... describes it as “semi-cardoid transmission line.” It has solid walls on three sides, while the rear is a perforated grill. The interior is stuffed“ ”woofers work only from approximately 150 Hz and down”
planet10 Posted May 3, 2021 Posted May 3, 2021 I am not a big fan of the TB. Too coloured for me. The Heil Bass Array was first shown (to the best of my knowledge) at the last Eropean Triode Festival. Used 15” JBLs. I just hate seeing translam boxes. Such a waste of materials. dave
crtexcnndrm99 Posted May 3, 2021 Posted May 3, 2021 On 03/05/2021 at 1:16 AM, planet10 said: I am not a big fan of the TB. Too coloured for me. The Heil Bass Array was first shown (to the best of my knowledge) at the last Eropean Triode Festival. Used 15” JBLs. I just hate seeing translam boxes. Such a waste of materials. dave Expand Thanks, I believe they also mentioned Lowthers. I’m sure fostex 8” -er could be substituted in too. Haven’t heard the heil bass concept, but intrigued. A stack of 15” would be insane. agrred that a crazy amount of materials goes into this style cabinet. Have seen a few Tannoy BLH cabinets made translam... that’s a tonne of mdf!
itsparks Posted May 3, 2021 Posted May 3, 2021 On 03/05/2021 at 1:16 AM, planet10 said: I am not a big fan of the TB. Too coloured for me. The Heil Bass Array was first shown (to the best of my knowledge) at the last Eropean Triode Festival. Used 15” JBLs. I just hate seeing translam boxes. Such a waste of materials. dave Expand I hate seeing people spend their money on speakers with painted on dots that does SFA ! 1
Red MacKay Posted May 3, 2021 Posted May 3, 2021 OK - I'll bite. What is "translam"? And what is the Heil Bass Array?
crtexcnndrm99 Posted May 3, 2021 Posted May 3, 2021 On 03/05/2021 at 8:36 AM, Red MacKay said: OK - I'll bite. What is "translam"? And what is the Heil Bass Array? Expand I was guessing that it was the process of laminating/stacking many identical pieces vertically to make the cabinet.. a la this 1
mwhouston Posted May 4, 2021 Posted May 4, 2021 Wanted to listen to my new modified speakers in my main listening room. And wanted to use my 6L6 SE UL wine box amp (Silver Supreme) to power them being 96db efficient. But when I turned on the power amp there was an audible hum in the left channel. This amp has always been dead quiet even with high sensitive speakers. I checked wiring in the amp and could find nothing and decided to swap out some tubes. First the driver tube (Psvane 12AT7), made no difference. Then i went to swap the power tubes and realised the tube was an EL34 and not a JJ 6L6GC. The 6L6s are quite fat and the EL34 slim. Now i remember, months ago i swapped in the EL34s to see how they sound and i got a hum. My intention was to put back the 6L6s but went back to my SS Holton and forgot the swap out. Now months down the road i remember. After an hour of stuffing around. Well worth the effort. The new speakers sound glorious and tube rich on the hot end of the JJs and silver foil MCaps. Im a happy man. https://retro-thermionic.blogspot.com/2017/02/silver-supreme-6l6-se-ul-amp-in-wooden.html 4
RePete Posted May 4, 2021 Posted May 4, 2021 On 21/04/2021 at 5:53 AM, Mark_A_W said: My own design. Fully active with Minidsp (2 off 2x4s) and a 6 Channel Rotel amp. The box is a tad small for the 8" woofers, but they needed to fit on the desk. They are massive overkill for PC speakers. But once you start building...it's hard to stop. Step 1: Design CNC Router Step 2: Build CNC Router Step 3: Buy Mill and convert to CNC Step 4: Design speakers in MCAD and Speaker CAD (I like Vituix CAD now, I used to use Speaker Workshop. Bought and tried SoundEasy, but never got on top of it.) Step 5: Buy MDF... Expand Beautiful work Mark. You mustn’t sleep much 1
mwhouston Posted May 6, 2021 Posted May 6, 2021 Im not getting emails from SNA. Do i have to clean out a mailbox or something? If so how?
mwhouston Posted May 6, 2021 Posted May 6, 2021 Under the current setup i wasn’t getting extended bass. Moved the new speakers over to the DIY Holton now flat down to 30hz. Even output at 25hz. Could rival my old main speakers which also get down to 30hz. New drivers still tight. So I’m expecting better performance in 50hours of play or so. 1
Bunno77 Posted May 6, 2021 Posted May 6, 2021 @mwhouston I saw them in altronics the other day. Pretty decent looking drivers 1
mwhouston Posted May 6, 2021 Posted May 6, 2021 On 06/05/2021 at 5:50 AM, Bunno77 said: @mwhouston I saw them in altronics the other day. Pretty decent looking drivers Expand With an Fs of 25hz and - in my boxes - 96db efficiency they are unbeatable at the price. 1
aussievintage Posted May 6, 2021 Posted May 6, 2021 On 06/05/2021 at 5:43 AM, mwhouston said: Im not getting emails from SNA. Do i have to clean out a mailbox or something? If so how? Expand They reset all the notification setup. You have to dig into your account settings to make it all work they way you want again. 1
mwhouston Posted May 6, 2021 Posted May 6, 2021 On 06/05/2021 at 6:20 AM, aussievintage said: They reset all the notification setup. You have to dig into your account settings to make it all work they way you want again. Expand I have re-setup my email, confirmed and activated it but still no email from SNA. Who do i PM to fix this.
aussievintage Posted May 6, 2021 Posted May 6, 2021 On 06/05/2021 at 8:35 AM, mwhouston said: I have re-setup my email, confirmed and activated it but still no email from SNA. Who do i PM to fix this. Expand Did you go into notifications and set them up again? Go to Account settings, and over on the right, under Other settings, is Notification settings. Lots of stuff in there will be set to NOT email you. 2
mwhouston Posted May 7, 2021 Posted May 7, 2021 (edited) A $20 TDA7293 100W chip amp kit with PS onboard. Completed the pcb. some months back and now a going amp. I had a spare 300VAC 30-0-30V tranni over from other builds and now in good use. Sounds good so far and looks neat but of course needs some hours on it. The chip boasts bi-polar front end with for sonics DMO back end for power. As long as it sounds good and performs quietly it could be made from chewing gum. $20 for a 100Wpc super low distortion amp, hard to beat. You could make it in a day. Edited May 7, 2021 by mwhouston 3
mwhouston Posted May 7, 2021 Posted May 7, 2021 If anyone is interested to build the 100W chip amp here is the link. https://www.aliexpress.com/item/32887903914.html
Steffen Posted May 7, 2021 Posted May 7, 2021 On 07/05/2021 at 3:16 AM, mwhouston said: Expand I obviously can’t see the whole story from the picture, but that ground wire to the transformer bolt worries me. If the transformer is bolted to the chassis without insulation, wouldn’t that create a short winding? 1
bob_m_54 Posted May 7, 2021 Posted May 7, 2021 On 07/05/2021 at 1:19 PM, Steffen said: I obviously can’t see the whole story from the picture, but that ground wire to the transformer bolt worries me. If the transformer is bolted to the chassis without insulation, wouldn’t that create a short winding? Expand Mounting kits have an insulator disc that goes either side of the transformer. One between the chassis and the transformer, and the other between the top metal disc and the transformer. I'd be more worried about whether the bolt is properly earthed to the chassis. You can't tighten the bolt too tight, and the head needs to have contact with bare metal (no paint) preferably with a shakeproof washer between the bolt head and the bare metal of the case. 1
Steffen Posted May 7, 2021 Posted May 7, 2021 On 07/05/2021 at 3:00 PM, bob_m_54 said: ]You can't tighten the bolt too tight, and the head needs to have contact with bare metal (no paint) preferably with a shakeproof washer between the bolt head and the bare metal of the case. Expand As long as you don’t create a conductive path around the transformer core, you should be fine. If that were to happen I suppose the green and yellow plastic dripping off the ground wire would be a sure sign
bob_m_54 Posted May 7, 2021 Posted May 7, 2021 (edited) On 07/05/2021 at 3:12 PM, Steffen said: As long as you don’t create a conductive path around the transformer core, you should be fine. If that were to happen I suppose the green and yellow plastic dripping off the ground wire would be a sure sign Expand Unlikely because you have two layers of insulation. The wrapping on the transformer, and the insulating discs. Even overtightening the bolt it would be difficult to do. But earth studs should be solidly bolted to the case/chassis, with a very good/clean contact to bare metal. Edit: 3 layers of insulation if you count the enamel on the wire as well. Edited May 7, 2021 by bob_m_54
mwhouston Posted May 7, 2021 Posted May 7, 2021 On 07/05/2021 at 1:19 PM, Steffen said: I obviously can’t see the whole story from the picture, but that ground wire to the transformer bolt worries me. If the transformer is bolted to the chassis without insulation, wouldn’t that create a short winding? Expand Yes I've heard this tale a few times but yet to ever see it actually happening. I get it but toroid trannis are both good and bad. They are bad because there is very little iron in their core and that is why they saturate on the tiniest amount of DC on the mains (all mains has DC) and don’t work as they should. A DC blocker fixes that. Because their cores are weak noise from the mains is not blocked and gets into the windings and the amp electronics. Cheap RFI/EMI filters can help here. And toroid trannies are good because they leak little flux into the neighbouring sensitive electronics. Because of the low flux leak i cannot image any real voltages being generated into a single bolt well away from the windings within the tranni. In fact it may guide flux away from the externals of the tranni. A good thing. Further more a single bolt is an open magnetic cct. and any flux occurring in the bolt would be immeasurably week. Therefore any current flowing through the bolt would also be extremely small. Now don’t forget any current attempting to flow through the bolt will meet eddy currents which will appose those very week currents being generated. Thanks eddy. Put up your hand if you have seen an amp burst into flames due to the earthed bolt holding down the tranni. I rest my case.
aussievintage Posted May 8, 2021 Posted May 8, 2021 On 07/05/2021 at 11:58 PM, mwhouston said: They are bad because there is very little iron in their core and that is why they saturate on the tiniest amount of DC on the mains (all mains has DC) and don’t work as they should. Expand Actually, I think it's because they have a low reluctance magnetic circuit, not because of the lack of iron. Putting a gap in the circuit, is what lets transformers tolerate DC - hence the way they construct transformers for SET amps. Of course, the downside is that they are less efficient. 1
mwhouston Posted May 8, 2021 Posted May 8, 2021 On 08/05/2021 at 12:27 AM, aussievintage said: Actually, I think it's because they have a low reluctance magnetic circuit, not because of the lack of iron. Putting a gap in the circuit, is what lets transformers tolerate DC - hence the way they construct transformers for SET amps. Of course, the downside is that they are less efficient. Expand No gaps in toroid power trannies. Low iron makes them cheaper to make and ship.
Recommended Posts