Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Topic started by: galyons on March 01, 2013, 11:54:03 AM

Title: Altec 70v 8w tranny for Paramour 1
Post by: galyons on March 01, 2013, 11:54:03 AM
Hey,
Would these 70v trannies work on a Paramour 1 to replace the Speco? They are Altec Lansing 8W.  There is a 1w tap, not 1.25 as in the Speco.  The big question is "Would they be better?"

Cheers,
Geary

Title: Re: Altec 70v 8w tranny for Paramour 1
Post by: Paul Joppa on March 08, 2013, 05:57:20 PM
Weird - the table is backwards; using the whole winding gives the highers impeedance and the lowest power at 70 volts, so if the diagram is correct then the brown wire is the 1-watt tap. That's pretty close to the 8K 1.25 watt tap of the Speco. You can check by measuring the DC resistance from black (common) to each of the other wires.

Will it sound better? Only one way to tell!  :^)

I'd start with the highest-impedance tap, brown in the diagram, and try each of the secondary taps. Then repeat with the red primary wire. You should have a good idea of what sounds best by that time...
Title: Re: Altec 70v 8w tranny for Paramour 1
Post by: galyons on May 20, 2013, 06:07:56 PM
Time has passed. Paramour has been "converted" to 45.  Quite honestly I have gotten so enthralled with the 45's that everything else went on the back-burner so I could just listen! Now....

Different Altec Lansing transformer for possible upgrade from the Speco's.  I picked this transformer because:



So the plan is to move forward.  I was planning to do the MQ upgrade, but with the 45 conversion, I backed off due to the lower output impedance of the BH-5's. If this works, should my future upgrade path be the EXO-45 instead of the BH-5? .

Can I just follow the "Iron Upgrade" directions in the archives for just the OPT? Do I need to change the cathode resistor, (now1k6 10w), and/or a further reduction of the high voltage, (now 1k6 10w resistor)?

Cheers,
Geary



 
Title: Re: Altec 70v 8w tranny for Paramour 1
Post by: galyons on June 16, 2013, 07:02:13 AM
Put in the Atec Lansing trannies....Wow!  (connected the 1w/com and 8 ohm/com)

 They are great, in every perceivable way!   ;D   Most noticeable is much better bass, not necessarily deeper, (My speakers don't go much below 50Hz), but tightness, clarity and impact are all significantly better.  Imaging and soundstaging are improved with much better palpable presence.  The soundstage is deeper, especially noticeable on small orchestral pieces with the brass instruments in the back row.

The overall voice and instrumental timbre seem more "real", especially brass instruments.

This was an easy change. Although the Altec trannies are larger, they just fit the original OPT holes.

I plan to get another pair to try with the 2A3's.   I think I will need to adjust the the cathode resistor size fr the 5K versus 4K OPT impedence.  I 'll try to find PJ's post...(unless someone has it to hand!)

Cheers,
Geary

 
Title: Re: Altec 70v 8w tranny for Paramour 1
Post by: galyons on June 16, 2013, 07:42:46 AM
Here is PJ's post, specifically for the Paramour2 to SR45 conversion:

* At various times I suggested three different operating points for the 45, depending on the output transformer impedance:

3K impedance: 250v at 36mA (standard), 1300 ohm cathode resistor
4K impedance: 250v at 31mA, 1550 ohm cathode resistor
5K impedance: 250v at 28mA, 1830 ohm cathode resistor

These had inconsistent estimates of the available power which I won't repeat, but they were generally in the range of 1.5 to 2 watts maximum.

Do these values hold true for a Paramour 1?  They seem to be consistent, but just double checking, before I pull the 1K6 ohm and replace with 1K8 ohm.

Cheers,
Geary