A new Linear TL Floor Standers for my next upgrade to 845 tubes

[Hari Iyer]

@ Kanwar, Will go by your wisdom and try to source these components. Do all resistors have to be film type or only the one which is in series with the signal. Same for capacitors.

Also the capacitors used for impedance matching and resonance shaping that are not in series with the signal need not be top grade as per my knowledge. Pls. advise.

 

[kanwar]

@ Kanwar, Will go by your wisdom and try to source these components. Do all resistors have to be film type or only the one which is in series with the signal. Same for capacitors.

Preferably Yes, whether series or shunt, they are always in signal path. Even your PCB [If you use any] on which you mount your components is a part of parasitic signal path.

Also the capacitors used for impedance matching and resonance shaping that are not in series with the signal need not be top grade as per my knowledge. Pls. advise.

When you speak about impedance matching or resonance shaping it automatically dictates that they are path to Audio current only.

Just another view: Don't fall in the trap of so called audiophile grade capacitors. Use Industrial grade stuff such as Epcos, Ctr, Alcon, Siemens. You will be amazed with the results.

 

[keith_correa]

Just another view: Don't fall in the trap of so called audiophile grade capacitors. Use Industrial grade stuff such as Epcos, Ctr, Alcon, Siemens. You will be amazed with the results.

And charge couple them

 

[kanwar]

And charge couple them

For that we need Phantom's power

 

[Hari Iyer]

I made the modifications to the crossover components and replaced all WW resistors with metal oxides and all Non-polars with Polyproplene capacitors. I noticed that with the modification the highs were very rounded and became even more smooth. I actually had to tweak the crossover with this refinement and now they sound well integrated with the lows with all the high-freq distortion / fatigue vanishing.
The learning is that never use WW / Fusible resistors even for testing a cross-over as the high frequency distortion with these will tempt you to reduce the level.

 

[keith_correa]

I made the modifications to the crossover components and replaced all WW resistors with metal oxides and all Non-polars with Polyproplene capacitors. I noticed that with the modification the highs were very rounded and became even more smooth. I actually had to tweak the crossover with this refinement and now they sound well integrated with the lows with all the high-freq distortion / fatigue vanishing.
The learning is that never use WW / Fusible resistors even for testing a cross-over as the high frequency distortion with these will tempt you to reduce the level.

Hari, where do you get the resistors and Polypropylene caps in Mumbai? Any particular brands you have good experiences with?

 

[kanwar]

@ Kanwar, Will go by your wisdom and try to source these components. Do all resistors have to be film type or only the one which is in series with the signal. Same for capacitors.

Also the capacitors used for impedance matching and resonance shaping that are not in series with the signal need not be top grade as per my knowledge. Pls. advise.

I made the modifications to the crossover components and replaced all WW resistors with metal oxides and all Non-polars with Polyproplene capacitors. I noticed that with the modification the highs were very rounded and became even more smooth. I actually had to tweak the crossover with this refinement and now they sound well integrated with the lows with all the high-freq distortion / fatigue vanishing.
The learning is that never use WW / Fusible resistors even for testing a cross-over as the high frequency distortion with these will tempt you to reduce the level.

Great! :clapping:

 

[SIDEWINDER18X]

I made the modifications to the crossover components and replaced all WW resistors with metal oxides and all Non-polars with Polyproplene capacitors.
The learning is that never use WW / Fusible resistors even for testing a cross-over as the high frequency distortion with these will tempt you to reduce the level.

Use ceramic non-inductive resistors & metalized polyester capacitors in x-overs.
By the way, Audio grade component are not bluff. Though industrial grade component also works well if you are less concern towards hi end sounding stuff.
See how hi end boxes from JM LABS, FOCAL, B&W, ATC and others do it.
Vivek

 

[SIDEWINDER18X]

Hari, where do you get the resistors and Polypropylene caps in Mumbai? Any particular brands you have good experiences with?

HTR India makes ceramic non -inductive resistors in different ratings and mounting styles.

For quality components you can visit .....
Precious Electronics Pvt.Ltd.
Chhotani Building, 52-C, Proctor Road,
Grant Road (E)
Mumbai - 400 007

 

[Hari Iyer]

Hari, where do you get the resistors and Polypropylene caps in Mumbai? Any particular brands you have good experiences with?

You get the metal oxide resistor & Polypropylene caps at Tejus / Mahavir at Lamington Road. Metal oxide you get only watts / 3 watts. Since i use parallel combination i am able to get around 5 watts. No particular brand in mind but they may be from Korea. Caps are from DEC. Some Japanese brands are also available at half the cost but i find them risky to purchase.

 

[keith_correa]

HTR India makes ceramic non -inductive resistors in different ratings and mounting styles.

Their website lists HEA, HCA & HCW ceramic types which they say are available in a non-inductive type. What's the difference between these [HEA/HCA/HCW] and which is the one that is best suited?

 

[Hari Iyer]

Finally this is what i settled for with my Tangband and Vifa drivers.

FR is almost flat and extended till the high frequency, impedance phase is also flat with less than 10 deg phase and impedance almost ruler flat from 1.3Khz onwards. Overall a very nice presentation of vocals, lows and highs and a much balanced sound stage which does not add or subtract anything from the recordings.

 

[jls001]

Resistors are available here.

Caps here.

 

[Hari Iyer]

Measured impedance response of the advance TL. The impedance at resonance is almost flat allowing better low frequency control and damping. The tuning Q of the line helps to lower the impedance at resonance significantly there by allowing constant loading to the amplifier and better power transfer.

 

[Hari Iyer]

Today after listening to the speakers in the afternoon removed some of the stuffing by 10% to increase the low end. The result was better low end extension and less compression in the low end. Wonder if the Tangband TS parameters are same as per the data sheet. Anyways now the lows are refined and without any compression after manual adjustments of the stuffing. The stuffing fine tune is most important in any TL design as per my experience.

 

[shafic]

Today after listening to the speakers in the afternoon removed some of the stuffing by 10% to increase the low end. The result was better low end extension and less compression in the low end. Wonder if the Tangband TS parameters are same as per the data sheet. Anyways now the lows are refined and without any compression after manual adjustments of the stuffing. The stuffing fine tune is most important in any TL design as per my experience.

Sir,

We enjoyed your kind hospitality and heard your TL speakers with nice 300B tube mono blocks. The experience was wonderful.

Yes i felt the low end extension was little loose. I hope now it is refined.

I appreciate your efforts/skills to make these nice looking speakers. The build quality and finishing of the cabinets are excellent. :clapping:

The "FULL" 'Digree' ( filter) coffee on a typical Bombay rainy day was worth remembering.

regds,

shafic

 

[hemantwaghe]

Yes Hari it was a very nice and warm experience at your place . Really liked the finish of the speakers . and that deadly madras filter coffee and dosas were a real treat ! Wish you all the very best for new assignment!

 

[kapvin]

Today after listening to the speakers in the afternoon removed some of the stuffing by 10% to increase the low end. The result was better low end extension and less compression in the low end. Wonder if the Tangband TS parameters are same as per the data sheet. Anyways now the lows are refined and without any compression after manual adjustments of the stuffing. The stuffing fine tune is most important in any TL design as per my experience.

i gave you the measured T/S parameters.

what I last saw was that your enclosure was acting as a kind of aperiodic enclosure. which explains the single, mild system impedance peak just around the Fo of the woofer. that plays well with the room gain of a smallish room

if you reduce the stuffing, you will get more bass for sure, as less of the backwave will be damped, but it will be peaky and around the line length tuning. have discussed this with you before. you may wish to consider converting it into a MLTL design, which should be simple to excute. you will need to close the open end, and put a port there. if you give me the box dimensions, i can model it for you. (I am anyway going to be working out a box model for another FM who pm'd me.)

Should give you 10-15hz extension beyond Fo. we can look at 2 tunings - maximally flat - for larger room, and max extension, which can use room gain to go really low in a smaller room.

best wishe

best wishes

 

[Hari Iyer]

Thanks for your time for offer of modelling the speakers with the mathcad.

This being an alpha TL, the line length does not follow the classic TL model as per Martin King's TL alingnment.

The line length is around 43" and the line is tuned to around 72Hz which is 20% more than resonance of 59Hz. The cross section area is i think 43 sq.inch.

There is no off-set from the closed end and is a exo-linear design.

Do let me know if you require any additional data.

 

[kapvin]

Hi Hari,

this is the modelled TL response based on your Geometry.



and this is the modelled impedance



the dotted lines are infinite baffle and solid line is your enclosure.

impedance looks familiar?